A187123 Row sums of triangle A187120.

1, 4, 22, 164, 1599, 19624, 292799, 5162063, 105139954, 2430528374, 62877375426, 1799698534522, 56461862815496, 1926534563625822, 71024188655886038, 2813193432059656268, 119136308527407025379, 5371507426340905440926

Offset: 3

Author

Paul D. Hanna, Mar 08 2011

Keywords

• nonn

Comments

Definition of triangle: A187120(n,k) = [y^k] R_{n-1}(y+y^2) for k=3..n, n>3, where R_n(y) is the n-th row polynomial starting with R_3(y)=y^3.

Crossrefs

Cf. A187120, A135083, A187121, A187122, A187124.

Programs

PARI

{a(n)=local(Rn=y^3);for(m=3,n-1,Rn=subst(truncate(Rn),y,y+y^2+O(y^m)));subst(truncate(Rn),y,1)}