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A082413
a(n) = (2*9^n + 3^n)/3.
3
1, 7, 57, 495, 4401, 39447, 354537, 3189375, 28700001, 258286887, 2324542617, 20920765455, 188286534801, 1694577750327, 15251196564297, 137260759512735, 1235346806916801, 11118121176157767, 100063090327139577, 900567812169415215
OFFSET
0,2
COMMENTS
Binomial transform of A082412.
FORMULA
G.f.: (1-5*x)/((1-3*x)*(1-9*x));
E.g.f.: (2*exp(9*x) + exp(3*x))/3.
a(n) = (2*9^n + 3^n)/3.
MAPLE
seq((2*9^n+3^n)/3, n=0..19); # Nathaniel Johnston, Jun 26 2011
CROSSREFS
Sequence in context: A349303 A268316 A291537 * A142990 A202250 A147689
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 23 2003
STATUS
approved