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A187008
Row sums of triangle A187005.
6
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.
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