A073187 Triangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows.

1, 1, 2, 5, 1, 14, 5, 42, 21, 132, 84, 3, 429, 330, 28, 1430, 1287, 180, 4862, 5005, 990, 12, 16796, 19448, 5005, 165, 58786, 75582, 24024, 1430, 208012, 293930, 111384, 10010, 55, 742900, 1144066, 503880, 61880, 1001, 2674440, 4457400, 2238390

Offset: 1

Author

Michael Somos, Jul 19 2002

Keywords

• nonn
• tabf

Examples

			1;
1;
2;
5,  1;
14, 5;
42, 21;
132, 84, 3;
429, 330, 28;
1430, 1287, 180; ...
		

Links

• G. C. Greubel, Rows n=0..150 of triangle, flattened

Crossrefs

Row sums give A071969.

Programs

Mathematica

T[n_, k_]:= If[k < 0 || k > n/3, 0, Binomial[n + 1, k]*Binomial[2*n - 3*k, n - 3*k]/(n + 1)]; Table[T[n, k], {n,0,10}, {k,0,Floor[n/3]}]//Flatten (* G. C. Greubel, May 29 2018 *)

PARI

alias(C,binomial); T(n,k)=if(k<0 || k>n/3,0,C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1))