A328606 Expansion of (1 + 9*x) / (1 - 2*x - 11*x^2).
1, 11, 33, 187, 737, 3531, 15169, 69179, 305217, 1371403, 6100193, 27285819, 121673761, 543491531, 2425394433, 10829195707, 48337730177, 215796613131, 963308258209, 4300379260859, 19197149362017, 85698470593483, 382565584169153, 1707814344866619, 7623850115593921, 34033658024720651
Offset: 0
Links
- Colin Barker, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (2,11).
Programs
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PARI
Vec((1 + 9*x) / (1 - 2*x - 11*x^2) + O(x^30)) \\ Colin Barker, Dec 13 2019
Formula
a(n) = 2*a(n-1) + 11*a(n-2) for n>1. - Colin Barker, Oct 21 2019
a(n)/a(n-1) ~ 1 + 2*sqrt(3).