A107249 A number triangle with repeated columns of binomial coefficients.

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 2, 2, 1, 1, 6, 3, 3, 2, 1, 1, 10, 6, 6, 3, 3, 1, 1, 20, 10, 10, 6, 4, 3, 1, 1, 35, 20, 20, 10, 10, 4, 4, 1, 1, 70, 35, 35, 20, 15, 10, 5, 4, 1, 1, 126, 70, 70, 35, 35, 15, 15, 5, 5, 1, 1, 252, 126, 126, 70, 56, 35, 21, 15, 6, 5, 1, 1, 462, 252, 252, 126, 126

Offset: 0

Author

Paul Barry, May 14 2005

Keywords

• easy
• nonn
• tabl

Comments

Reversal of A096921. Row sums are A026010. Diagonal sums are 107250.

Examples

			Triangle begins
1;
1,1;
1,1,1;
2,1,1,1;
3,2,2,1,1;
6,3,3,2,1,1;
10,6,6,3,3,1,1;
		

Formula

Number triangle T(n, k)=C(floor((2n-k-2)/2), floor((n-k)/2))