A179904 a(n) = A056520(n)+1 for n>0, a(0)=1.
1, 3, 7, 16, 32, 57, 93, 142, 206, 287, 387, 508, 652, 821, 1017, 1242, 1498, 1787, 2111, 2472, 2872, 3313, 3797, 4326, 4902, 5527, 6203, 6932, 7716, 8557, 9457, 10418, 11442, 12531, 13687, 14912, 16208, 17577, 19021, 20542, 22142, 23823, 25587
Offset: 0
Examples
a(3) = 16 = 1 + A056520(3) = (1 + 15). a(4) = 32 = (9, 7, 5, 3, 1) dot (1, 0, 2, 3, 4) = (9 + 0 + 10 + 9 + 4).
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..10000
- Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
Programs
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Mathematica
LinearRecurrence[{4,-6,4,-1},{1,3,7,16,32},50] (* Harvey P. Dale, Apr 25 2020 *)
Formula
From Bruno Berselli, Aug 26 2011: (Start)
G.f.: (1 + x)*(1 - 2*x + 3*x^2 - x^3)/(1 - x)^4.
a(n) = (1/6)*(2*n^3 + 3*n^2 + n + 12) for n>0, a(0)=1. (End)
a(n) = A153056(n) for n > 0. - Georg Fischer, Oct 24 2018
Extensions
More terms and a(20) added by Bruno Berselli, Aug 26 2011
Comments