A122887 - OEIS

%I #3 Mar 30 2012 18:36:59

%S 1,10,118,1656,27326,520626,11271436,273613032,7365210840,

%T 217823497200,7022714928604,245186433880584,9217032342988575,

%U 371216529334562246,15948164256621353088,728062466187371268960,35197679178007576031784

%N An upper diagonal of table A122888.

%o (PARI) {a(n)=local(F=x+x^2, G=x+x*O(x^(n+1))); if(n<3, 0, for(i=1, n-2, G=subst(F, x, G)); return(polcoeff(G, n+0, x)))}

%Y Cf. A122888; A122892.

%K nonn

%O 4,2

%A _Paul D. Hanna_, Sep 18 2006