A059145 - OEIS

A059145

A hierarchical sequence (S(W3{2,2}*cc) - see A059126).

15, 54, 141, 324, 699, 1458, 2985, 6048, 12183, 24462, 49029, 98172, 196467, 393066, 786273, 1572696, 3145551, 6291270, 12582717, 25165620, 50331435, 100663074, 201326361, 402652944, 805306119, 1610612478, 3221225205, 6442450668, 12884901603, 25769803482

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

LINKS

Table of n, a(n) for n=0..29.

Jonas Wallgren, Hierarchical sequences

Index entries for linear recurrences with constant coefficients, signature (4, -5, 2).

FORMULA

Conjectures from Colin Barker, Oct 07 2015: (Start)

a(n) = 3*(-11 + 2^(4+n) - 3*n) = 3*A109363(n+2).

a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) for n > 2.

G.f.: 3*(2*x-5) / ((x-1)^2*(2*x-1)).