A187008 - OEIS

%I #4 Mar 30 2012 18:37:26

%S 1,2,5,18,96,733,7501,97054,1521112,28005248,592218737,14141289480,

%T 376251253450,11036022346816,353747961265089,12301349824260074,

%U 461216257715290976,18545829116907146812,796122011317944176206

%N  Row sums of triangle A187005.

%C  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.

%o  (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)}

%Y  Cf. A187005, A135081, A187006, A187007, A187009.

%K nonn

%O 1,2

%A _Paul D. Hanna_, Mar 02 2011