A382677 a(n) = 9 - 28 * 2^n + 20 * 3^n.
1, 13, 77, 325, 1181, 3973, 12797, 40165, 124061, 379333, 1152317, 3485605, 10514141, 31657093, 95200637, 286060645, 859099421, 2579133253, 7741069757, 23230549285, 69706327901, 209148343813, 627503751677, 1882628695525, 5648120967581, 16944832664773
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (6,-11,6).
Programs
-
PARI
a(n) = 9-28*2^n+20*3^n;
Formula
From Stefano Spezia, Aug 30 2025: (Start)
G.f.: (1 + 2*x)*(1 + 5*x)/((1 - x)*(1 - 2*x)*(1 - 3*x)).
E.g.f.: exp(x)*(2*exp(x) - 1)*(10*exp(x) - 9). (End)