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A030056 C(2n+1,n-6). 4
1, 15, 136, 969, 5985, 33649, 177100, 888030, 4292145, 20160075, 92561040, 417225900, 1852482996, 8122425444, 35240152720, 151532656696, 646626422970, 2741188875414, 11554258485616, 48459472266975 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,2

LINKS

Chai Wah Wu, Table of n, a(n) for n = 6..500

Milan Janjic, Two Enumerative Functions

FORMULA

a(n+1) = a(n)*(2*n+2)*(2*n+3)/((n-5)*(n+8)). - Chai Wah Wu, Jan 26 2016

PROG

(Python)

from __future__ import division

A030056_list, b = [], 1

for n in range(6, 501):

    A030056_list.append(b)

    b = b*(2*n+2)*(2*n+3)//((n-5)*(n+8)) # Chai Wah Wu, Jan 26 2016

CROSSREFS

Diagonal 14 of triangle A100257.

Sequence in context: A155648 A126536 A299033 * A225978 A175707 A123955

Adjacent sequences:  A030053 A030054 A030055 * A030057 A030058 A030059

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified October 19 13:01 EDT 2019. Contains 328222 sequences. (Running on oeis4.)