login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A307522 Expansion of Product_{k>=1} ((1 + x)^k - x^k)/((1 + x)^k + x^k). 2
1, -2, 2, -2, 4, -10, 22, -42, 72, -116, 188, -332, 662, -1432, 3148, -6736, 13784, -26894, 50254, -90782, 160856, -285230, 518170, -983710, 1964800, -4090002, 8705322, -18582722, 39219572, -81148034, 163946630, -323136562, 622125982, -1173528562, 2179230066 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..34.

FORMULA

G.f.: theta_4(x/(1 + x)), where theta_4() is the Jacobi theta function.

PROG

(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, ((1+x)^k-x^k)/((1+x)^k+x^k)))

CROSSREFS

Cf. A002448, A307520, A307521, A318570.

Sequence in context: A293177 A231382 A213270 * A130707 A131562 A260786

Adjacent sequences:  A307519 A307520 A307521 * A307523 A307524 A307525

KEYWORD

sign

AUTHOR

Seiichi Manyama, Apr 12 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 22 19:16 EST 2020. Contains 331153 sequences. (Running on oeis4.)