A131091 Partial sums of A131707.
1, 2, 5, 12, 19, 20, 29, 38, 45, 48, 51, 60, 61, 62, 65, 72, 79, 80, 89, 98, 105, 108, 111, 120, 121, 122, 125, 132, 139, 140, 149, 158, 165, 168, 171, 180, 181, 182, 185, 192, 199, 200, 209, 218, 225, 228, 231, 240, 241, 242, 245, 252, 259, 260, 269, 278, 285
Offset: 0
Links
- Harvey P. Dale, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (2,-1,0,0,0,-1,2,-1).
Programs
-
Mathematica
Accumulate[PadRight[{},60,{1,1,3,7,7,1,9,9,7,3,3,9}]] (* Harvey P. Dale, Jul 30 2025 *)
Formula
O.g.f.: (9x^6-6x^5+4x^3+2x^2+1)/((x-1)^2*(x^2+1)*(x^4-x^2+1)). - R. J. Mathar, Jul 16 2008
a(n) = 2*a(n-1) - a(n-2) - a(n-6) + 2*a(n-7) - a(n-8) for n > 7. - Chai Wah Wu, Jan 09 2021
Extensions
Edited by R. J. Mathar, Jul 16 2008