A119732 f-Pascal's triangle where f(n) = n*(n+1)/2 = A000217(n).

1, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 11, 20, 11, 1, 1, 67, 276, 276, 67, 1

Offset

0,5

Links

Table of n, a(n) for n=0..20.

Formula

T(n,k) = f(T(n-1,k-1)) + f(T(n-1,k))where f(n) = n*(n+1)/2 = A000217(n); T(0;0) = 1 ; T(n,k) = 0 if k<0 or if k>n.

Example

Triangle begins:
1;
1, 1;
1, 2, 1;
1, 4, 4, 1;
1, 11, 20, 11, 1;
1, 67, 276, 276, 67, 1;

Crossrefs

Cf. A007318.

Sequence in context: A307139 A078121 A333157 * A260625 A306614 A264336

Adjacent sequences: A119729 A119730 A119731 * A119733 A119734 A119735

Keyword

nonn,tabl

Author

Philippe Deléham, Jun 14 2006

Status

approved