A187008 Row sums of triangle A187005.

1, 2, 5, 18, 96, 733, 7501, 97054, 1521112, 28005248, 592218737, 14141289480, 376251253450, 11036022346816, 353747961265089, 12301349824260074, 461216257715290976, 18545829116907146812, 796122011317944176206

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.

Links

Table of n, a(n) for n=1..19.

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

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

Sequence in context: A335547 A367012 A075441 * A333837 A075634 A322396

Adjacent sequences: A187005 A187006 A187007 * A187009 A187010 A187011

Keyword

nonn

Author

Paul D. Hanna, Mar 02 2011

Status

approved