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

0,7

Comments

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

Links

Table of n, a(n) for n=0..82.

Formula

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

Example

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;

Crossrefs

Sequence in context: A047040 A047020 A127832 * A062842 A126805 A288003

Adjacent sequences: A107246 A107247 A107248 * A107250 A107251 A107252

Keyword

easy,nonn,tabl

Author

Paul Barry, May 14 2005

Status

approved