OFFSET
21,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 21..400
MAPLE
b:= proc(x, y, t) option remember; `if`(y<0 or y>x, 0, `if`(x=0, 1,
series(b(x-1, y+1, [2, 2, 4, 5, 6, 2, 4, 2, 10, 2][t])+`if`(t=10,
z, 1)*b(x-1, y-1, [1, 3, 1, 3, 3, 7, 8, 9, 1, 3][t]), z, 6)))
end:
a:= n-> coeff(b(2*n, 0, 1), z, 5):
seq(a(n), n=21..50);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 13 2014
STATUS
approved