login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A165935
a(n) = (-1)^(n-1)*n*(4n^2-5)^2.
1
1, -242, 2883, -13924, 45125, -115926, 255367, -504008, 915849, -1560250, 2523851, -3912492, 5853133, -8495774, 12015375, -16613776, 22521617, -30000258, 39343699, -50880500
OFFSET
1,2
COMMENTS
These are the partial sums of the alternating series of odd fifth powers beginning with 1. See A016757.
FORMULA
G.f.: x*(1-236*x+1446*x^2-236*x^3+x^4) / (1+x)^6. - R. J. Mathar, Nov 27 2011
E.g.f.: x*(1 - 120*x + 360*x^2 - 160*x^3 + 16*x^4)*exp(-x). - Ilya Gutkovskiy, Apr 17 2016
MATHEMATICA
Table[(-1)^(n - 1)*n*(4*n^2 - 5)^2, {n, 1, 50}] (* G. C. Greubel, Apr 18 2016 *)
LinearRecurrence[{-6, -15, -20, -15, -6, -1}, {1, -242, 2883, -13924, 45125, -115926}, 20] (* Harvey P. Dale, Mar 24 2020 *)
PROG
(PARI) vector(100, n, (-1)^(n-1)*n*(4*n^2-5)^2) \\ Altug Alkan, Apr 18 2016
CROSSREFS
Cf. A016757.
Sequence in context: A258886 A354563 A354565 * A318529 A006601 A283723
KEYWORD
easy,sign
AUTHOR
Richard L. Peterson (rl_pete(AT)yahoo.com), Oct 01 2009
STATUS
approved