A145911 a(n) = A145909(n)/8.

0, 1, 1, 2, 10, 5, 7, 28, 4, 5, 55, 22, 26, 91, 35, 40, 136, 17, 19, 190, 70, 77, 253, 92, 100, 325, 39, 42, 406, 145, 155, 496, 176, 187, 595, 70, 74, 703, 247, 260, 820, 287, 301, 946, 110, 115, 1081, 376, 392, 1225, 425, 442, 1378

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..5000

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,0,-3,0,0,0,0,0,0,0,0,1).

Formula

a(n) = A106619(n)*A106619(n+1).

Maple

A061039:= proc(n) numer(1/9-1/n^2) ; end proc:
A145909:= proc(n) ; A061039(6*n+3); end proc:
A145911:= proc(n) ; A145909(n)/8; end proc:
seq(A145911(n), n=0..80) ; # R. J. Mathar, Jan 06 2011

Mathematica

Numerator[(1/9)*(1 -1/(2*Range[0, 75] +1)^2)]/8 (* G. C. Greubel, Mar 12 2022 *)

Prog

(Sage) [numerator((1/9)*(1 - 1/(2*n+1)^2))/8 for n in (0..75)] # G. C. Greubel, Mar 12 2022

Crossrefs

Cf. A061039, A106619, A145909.

Sequence in context: A000170 A038216 A213603 * A234041 A027626 A096668

Adjacent sequences: A145908 A145909 A145910 * A145912 A145913 A145914

Keyword

nonn,easy

Author

Paul Curtz, Oct 24 2008

Status

approved