A054133 - OEIS

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A054133

T(2n-1,n) where T is the array in A054126.

0

2, 7, 39, 236, 1479, 9418, 60492, 390720, 2534115, 16489802, 107594725, 703681448, 4611414244, 30273029080, 199045400424

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..15.

FORMULA

a(n) = A052509(4*n-2,3*n) + A052509(4*n-2,n-1) = 2^(n-2) + Sum_{m=0..n-1} binomial(3*n-1,m) for n >= 2. - Jianing Song, May 30 2022

PROG

(PARI) a(n) = if(n==1, 2, 2^(n-2) + sum(m=0, n-1, binomial(3*n-1, m))) \\ Jianing Song, May 30 2022

CROSSREFS

Sequence in context: A014058 A119602 A121752 * A330470 A364336 A266310

Adjacent sequences: A054130 A054131 A054132 * A054134 A054135 A054136

KEYWORD

nonn,more

AUTHOR

Clark Kimberling

EXTENSIONS

Definition clarified by Eric Rowland, May 29 2022

STATUS

approved