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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A291645 Expansion of the series reversion of -1 + Product_{k>=1} (1 + x^(k^2)). 0
1, 0, 0, -1, -1, 0, 4, 9, 4, -23, -78, -78, 132, 694, 1088, -443, -6169, -13452, -4646, 52247, 155891, 143796, -391672, -1715015, -2481013, 2107735, 17836000, 35704800, 3037215, -172386166, -465009936, -338007604, 1487272659, 5624864403, 7125599375, -10208041482 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

Reversion of g.f. (with constant term omitted) for A033461.

LINKS

Table of n, a(n) for n=1..36.

N. J. A. Sloane, Transforms

Eric Weisstein's World of Mathematics, Series Reversion

Index entries for reversions of series

FORMULA

G.f. A(x) satisfies: -1 + Product_{k>=1} (1 + A(x)^(k^2)) = x.

MATHEMATICA

nmax = 36; Rest[CoefficientList[InverseSeries[Series[-1 + Product[1 + x^k^2, {k, 1, nmax}], {x, 0, nmax}], x], x]]

CROSSREFS

Cf. A007312, A033461, A050393, A291489.

Sequence in context: A131016 A204996 A061369 * A340769 A088377 A066048

Adjacent sequences:  A291642 A291643 A291644 * A291646 A291647 A291648

KEYWORD

sign

AUTHOR

Ilya Gutkovskiy, Aug 28 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 23 04:46 EDT 2021. Contains 347609 sequences. (Running on oeis4.)