OFFSET
1,2
COMMENTS
Definition of triangle: A187005(n,k) = [y^k] R_{n-1}(y+y^2) for k=1..n where R_n(y) is the n-th row polynomial for n>1 with R_1(y)=y.
PROG
(PARI) {a(n)=local(Rn=y); for(m=1, n, Rn=subst(truncate(Rn), y, y+y^2+y*O(y^m))); subst(truncate(Rn), y, 1)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 02 2011
STATUS
approved