From: Leroy Quet on
Let H(0,m) = 1/m for all positive integers m.
Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n.
(So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.)

Let, for all positive integers k, j(2k) = i, the squareroot of -1.
Let , for all positive integers k, j(2k-1) = 1.

Does 0 =

sum{k=1 to infinity}
H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,

for all nonnegative integers n, and where arctan(pi/2) is in radians
and is the value between 0 and pi/2?

There are lots of places in my computations where I may have made at
least one error. But hopefully I didn't make any.

Thanks,
Leroy Quet

From: OwlHoot on
On Jul 3, 9:38 pm, Leroy Quet <qqq...(a)mindspring.com> wrote:
> Let H(0,m) = 1/m for all positive integers m.
> Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n.
> (So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.)
>
> Let, for all positive integers k,  j(2k) = i, the squareroot of -1.
> Let , for all positive integers k, j(2k-1) = 1.
>
> Does 0 =
>
> sum{k=1 to infinity}
>   H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,
>
> for all nonnegative integers n, and where arctan(pi/2) is in radians
> and is the value between 0 and pi/2?
>
> There are lots of places in my computations where I may have made at
> least one error. But hopefully I didn't make any.
>
> Thanks,
> Leroy Quet

I'd try running it through Mathematica. The Home edition
is only a couple of hundred dollars now.

It's brilliant - I've spent the last week working through
a good book called "A Student's Guide to Mathematica", by
B Torrence and E Torrence (2nd ed, 2009), and I highly
recommend it.

P.S. If you do buy it, be sure to install it on a PC with
up-to-date hardware and software, which you don't intend
changing for some years, or decades preferably, because
I gather that for copy protection reasons it is extremely
finicky about being transplanted from one PC or OS to
another!


Cheers

John Ramsden (jhnrmsdn(a)yahooo.co.uk) remove a letter to reply


P.S. Sorry - Can't help with the series - It just looks
too scary! But it's nice to see some of the regulars
still posting here on sci.math.
From: Sue San on

"Leroy Quet" <qqquet(a)mindspring.com> wrote in message
news:d2306d0a-fb62-454b-9e42-fcf82b05ca63(a)g19g2000yqc.googlegroups.com...
> Let H(0,m) = 1/m for all positive integers m.
> Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n.
> (So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.)
>
> Let, for all positive integers k, j(2k) = i, the squareroot of -1.
> Let , for all positive integers k, j(2k-1) = 1.
>
> Does 0 =
>
> sum{k=1 to infinity}
> H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,
>
> for all nonnegative integers n, and where arctan(pi/2) is in radians
> and is the value between 0 and pi/2?
>
> There are lots of places in my computations where I may have made at
> least one error. But hopefully I didn't make any.
>
> Thanks,
> Leroy Quet
>


The following is wrong, you are missing operators or ( ) or both;
and what is arctan(pi/2) doing in there ?? it is a constant.
Plase correct;

H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,


From: Leroy Quet on


Sue San wrote:
> "Leroy Quet" <qqquet(a)mindspring.com> wrote in message
> news:d2306d0a-fb62-454b-9e42-fcf82b05ca63(a)g19g2000yqc.googlegroups.com...
> > Let H(0,m) = 1/m for all positive integers m.
> > Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n.
> > (So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.)
> >
> > Let, for all positive integers k, j(2k) = i, the squareroot of -1.
> > Let , for all positive integers k, j(2k-1) = 1.
> >
> > Does 0 =
> >
> > sum{k=1 to infinity}
> > H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,
> >
> > for all nonnegative integers n, and where arctan(pi/2) is in radians
> > and is the value between 0 and pi/2?
> >
> > There are lots of places in my computations where I may have made at
> > least one error. But hopefully I didn't make any.
> >
> > Thanks,
> > Leroy Quet
> >
>
>
> The following is wrong, you are missing operators or ( ) or both;
> and what is arctan(pi/2) doing in there ?? it is a constant.
> Plase correct;
>
> H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,


Yes, arctan(pi/2) is a constant.

I checked this for n = 0, and it is WRONG. It seems, however, that a
simple fix would correct it. (My intent was valid, it seems.) But I do
not love this "result" enough to fix it now.

Thanks,
Leroy Quet

From: Rob Johnson on
In article <a06457a7-b0a4-4a57-9151-6bc251b118da(a)r27g2000yqb.googlegroups.com>,
Leroy Quet <qqquet(a)mindspring.com> wrote:
>Sue San wrote:
>> "Leroy Quet" <qqquet(a)mindspring.com> wrote in message
>> news:d2306d0a-fb62-454b-9e42-fcf82b05ca63(a)g19g2000yqc.googlegroups.com...
>> > Let H(0,m) = 1/m for all positive integers m.
>> > Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n.
>> > (So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.)
>> >
>> > Let, for all positive integers k, j(2k) = i, the squareroot of -1.
>> > Let , for all positive integers k, j(2k-1) = 1.
>> >
>> > Does 0 =
>> >
>> > sum{k=1 to infinity}
>> > H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,
>> >
>> > for all nonnegative integers n, and where arctan(pi/2) is in radians
>> > and is the value between 0 and pi/2?
>> >
>> > There are lots of places in my computations where I may have made at
>> > least one error. But hopefully I didn't make any.
>> >
>> > Thanks,
>> > Leroy Quet
>> >
>>
>>
>> The following is wrong, you are missing operators or ( ) or both;
>> and what is arctan(pi/2) doing in there ?? it is a constant.
>> Plase correct;
>>
>> H(n,k) e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2) * j(k) / (k+2n-1)!,
>
>
>Yes, arctan(pi/2) is a constant.
>
>I checked this for n = 0, and it is WRONG. It seems, however, that a
>simple fix would correct it. (My intent was valid, it seems.) But I do
>not love this "result" enough to fix it now.

I started working on this last night. I hadn't had any luck with
proving it, and I was going to check out the n = 0 case numerically
this morning. However, I came up with a couple of identities that
might help with the "fixed" problem.

i arctan(pi/2) 1 + i pi/2
e = ----------------
sqrt(1 + pi^2/4)

so that the part of the original formula

e^(i*k*arctan(pi/2)) * (1 +pi^2 /4)^(k/2)

reduces to

(1 + i pi/2)^k

Also, a closed formula for j(k) is

1 + i k 1 - i
j(k) = ----- - (-1) -----
2 2

I wouldn't mind working on the fixed problem tonight, if you don't
mind posting it.

Rob Johnson <rob(a)trash.whim.org>
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