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!)
A162680 G.f. is the polynomial (Product_{k=1..23} (1 - x^(3*k)))/(1-x)^23. 1
1, 23, 276, 2299, 14927, 80454, 374439, 1545807, 5771919, 19781035, 62936510, 187603065, 527817225, 1410264780, 3596907555, 8795685646, 20699124413, 47031284166, 103467710300, 220946372920, 458974273140, 929305397041 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

This is a row of the triangle in A162499. Only finitely many terms are nonzero.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..805

MAPLE

m:=23: seq(coeff(series(mul((1-x^(3*k)), k=1..m)/(1-x)^m, x, n+1), x, n), n=0..21); # Muniru A Asiru, Jul 07 2018

MATHEMATICA

CoefficientList[Series[Times@@(1-x^(3*Range[23]))/(1-x)^23, {x, 0, 30}], x] (* Harvey P. Dale, Jun 04 2017 *)

PROG

(PARI) x='x+O('x^50); A = prod(k=1, 23, (1-x^(3*k)))/(1-x)^23; Vec(A) \\ G. C. Greubel, Jul 0762018

(MAGMA) m:=50; R<x>:=PowerSeriesRing(Integers(), m); F:=(&*[(1-x^(3*k)): k in [1..23]])/(1-x)^23; Coefficients(R!(F)); // G. C. Greubel, Jul 06 2018

CROSSREFS

Sequence in context: A161523 A161930 A162365 * A010975 A022588 A268992

Adjacent sequences:  A162677 A162678 A162679 * A162681 A162682 A162683

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 02 2009

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 June 18 01:13 EDT 2021. Contains 345089 sequences. (Running on oeis4.)