A107030 Number triangle associated with the Riordan arrays (1/(1+x),x/(1+x)^k),k>=0.

1, 2, 1, 2, 2, 1, 2, 4, 2, 1, 2, 8, 6, 2, 1, 2, 16, 20, 8, 2, 1, 2, 32, 70, 38, 10, 2, 1, 2, 64, 252, 196, 62, 12, 2, 1, 2, 128, 924, 1062, 426, 92, 14, 2, 1, 2, 256, 3432, 5948, 3112, 792, 128, 16, 2, 1, 2, 512, 12870, 34120, 23686, 7302, 1326, 170, 18, 2, 1, 2, 1024, 48620

Offset

0,2

Links

Table of n, a(n) for n=0..68.

Formula

Number triangle T(n, k)=(k-1)*C(k(n-k), n-k)-(k-2)*sum{j=0..n-k, C(k(n-k), j)}

Example

Triangle begins
1;
2,1;
2,2,1;
2,4,2,1;
2,8,6,2,1;
2,16,20,8,2,1;

Crossrefs

Reversal of A107027. Row sums are A107028. Diagonal sums are A107031. Columns include A040000, A000079, A000984, A047098.

Sequence in context: A263666 A107027 A355395 * A271362 A354555 A263643

Adjacent sequences: A107027 A107028 A107029 * A107031 A107032 A107033

Keyword

easy,nonn,tabl

Author

Paul Barry, May 09 2005

Status

approved