OFFSET
2,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 2..464
MAPLE
b:= proc(u, o, c) option remember; `if`(c<0 or c>2, 0, `if`(u+o=0,
x^c, (p-> add(coeff(p, x, i)*x^max(i, c), i=0..2))(add(
b(u-j, o-1+j, c-1), j=1..u)+add(b(u+j-1, o-j, c+1), j=1..o))))
end:
a:= n-> coeff(add(b(j-1, n-j, 0), j=1..n), x, 2):
seq(a(n), n=2..30);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 25 2018
STATUS
approved