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A229277 Number of ascending runs in {1,...,3}^n. 2
0, 3, 15, 63, 243, 891, 3159, 10935, 37179, 124659, 413343, 1358127, 4428675, 14348907, 46235367, 148272039, 473513931, 1506635235, 4778186031, 15109399071, 47652720147, 149931729243, 470715894135, 1474909801623, 4613015762523, 14403906360531, 44906296300479 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

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

a(n) = 3^(n-1)*(2*n+1) for n>0, a(0) = 0.

a(n) = 3*A081038(n-1) for n>0.

MAPLE

a:= n-> `if`(n=0, 0, 3^(n-1)*(2*n+1)):

seq(a(n), n=0..30);

CROSSREFS

Column k=3 of A229079.

Sequence in context: A260326 A204086 A171761 * A218313 A218190 A216757

Adjacent sequences:  A229274 A229275 A229276 * A229278 A229279 A229280

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Sep 18 2013

STATUS

approved

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Last modified February 27 03:03 EST 2020. Contains 332299 sequences. (Running on oeis4.)