The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A283243 Expansion of exp( Sum_{n>=1} -sigma_2(3*n)*x^n/n ) in powers of x. 2
1, -10, 25, 53, -270, -77, 1057, 610, -2031, -5438, -1953, 17236, 34121, 3351, -103369, -195850, -55471, 468448, 1067785, 764094, -1430780, -4974559, -6242563, 334620, 16946199, 34459888, 29243953, -24503978, -124514921, -205795663, -140256312, 191109263 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = -(1/n)*Sum_{k=1..n} sigma_2(3*k)*a(n-k). - Seiichi Manyama, Mar 04 2017
PROG
(PARI) A283243_vec(m)=Vec(exp(sum(n=1, m, -sigma(3*n, 2)*x^n/n)+x*O(x^m))) \\ Yields m+1 terms a(0..m). - M. F. Hasler, Mar 05 2017
CROSSREFS
Cf. A283237 (sigma_2(3*n)), A283238 (exp( Sum_{n>=1} sigma_2(3*n)*x^n/n )).
Cf. exp( Sum_{n>=1} -sigma_k(3*n)*x^n/n ): A185654 (k=1), this sequence (k=2).
Cf. exp( Sum_{n>=1} -sigma_2(m*n)*x^n/n ): A073592 (m=1), A283242 (m=2), this sequence (m=3).
Sequence in context: A020179 A022670 A072277 * A263310 A063424 A137930
KEYWORD
sign
AUTHOR
Seiichi Manyama, Mar 03 2017
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 13 22:21 EDT 2024. Contains 373391 sequences. (Running on oeis4.)