OFFSET
0,8
FORMULA
A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} binomial(2*n-2*j+k,j)/(2*n-2*j+k) * A(n-j,j).
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, 1, ...
0, 1, 2, 3, 4, 5, 6, ...
0, 1, 3, 6, 10, 15, 21, ...
0, 3, 8, 16, 28, 45, 68, ...
0, 10, 27, 54, 95, 155, 240, ...
0, 46, 118, 228, 392, 631, 972, ...
0, 244, 609, 1144, 1916, 3015, 4560, ...
PROG
(PARI) a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n-2*j+k, j)/(2*n-2*j+k)*a(n-j, j)));
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Jun 04 2025
STATUS
approved
