A339028 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A339028

Triangle T(n,m) = 3*(m+1)*C(n+m+3,m)*C(2*n+2,n-m)/((n+m+3)*C(n+1,m)).

1, 3, 3, 9, 12, 9, 28, 42, 42, 28, 90, 144, 162, 144, 90, 297, 495, 594, 594, 495, 297, 1001, 1716, 2145, 2288, 2145, 1716, 1001, 3432, 6006, 7722, 8580, 8580, 7722, 6006, 3432, 11934, 21216, 27846, 31824, 33150, 31824, 27846, 21216, 11934, 41990, 75582, 100776, 117572, 125970, 125970, 117572, 100776, 75582, 41990

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

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..54.

FORMULA

G.f. ((sqrt(1-4*x*y)-sqrt(1-4*x))/(2*(x-x*y)))^3.

EXAMPLE

3,3,

9,12,9,

28,42,42,28,

90,144,162,144,