A107865 Matrix inverse of triangle A107862.

1, -1, 1, -1, -2, 1, -7, -4, -3, 1, -77, -26, -9, -4, 1, -1145, -287, -67, -16, -5, 1, -21410, -4412, -798, -139, -25, -6, 1, -481683, -86004, -13029, -1830, -251, -36, -7, 1, -12655196, -2017658, -268368, -32191, -3667, -412, -49, -8, 1, -379998938, -55134458, -6630228, -705680, -69868, -6657, -631

Offset

0,5

Comments

Matrix product with A107867 equals A107876.

Links

Table of n, a(n) for n=0..51.

Example

Triangle begins:
1;
-1,1;
-1,-2,1;
-7,-4,-3,1;
-77,-26,-9,-4,1;
-1145,-287,-67,-16,-5,1;
-21410,-4412,-798,-139,-25,-6,1;
-481683,-86004,-13029,-1830,-251,-36,-7,1; ...

Prog

(PARI) {T(n, k)=(matrix(n+1, n+1, r, c, if(r>=c, binomial((r-1)*(r-2)/2-(c-1)*(c-2)/2+r-c, r-c)))^-1)[n+1, k+1]}

Crossrefs

Cf. A107862, A107866 (column 0), A107867, A107870, A107876.

Sequence in context: A122843 A167196 A241881 * A089225 A185110 A343202

Adjacent sequences: A107862 A107863 A107864 * A107866 A107867 A107868

Keyword

sign,tabl

Author

Paul D. Hanna, Jun 04 2005

Status

approved