A118926 Invariant column vector V under matrix product A104546*V = V: a(n) = Sum_{k=0,[n/2]} A104546(n,k)*a(k).

1, 2, 7, 28, 125, 598, 3007, 15708, 84585, 466954, 2632167, 15103676, 88012801, 519848442, 3107443803, 18774545752, 114527169657, 704731976138, 4370943547471, 27306560735812, 171728169545661, 1086605771091766

Offset: 0

Author

Paul D. Hanna, May 06 2006

Keywords

• nonn

Comments

Triangle A104546(n,k) = the number of Schroeder paths of length 2n and having k platforms.

Crossrefs

Cf. A104546, A118927 (self-convolution square-root).

Programs

PARI

{a(n)=local(G=1+x+x*O(x^n));if(n==0,1, for(i=0,n,G=1+x*G+x*G*(G+(y-1)*x/(1-x))); sum(k=0,n\2,a(k)*polcoeff(polcoeff(G+y*O(y^k),n,x),k,y)))}

Formula

Self-convolution of A118927.