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

3,2

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.

Links

Table of n, a(n) for n=3..20.

Prog

(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)}

Crossrefs

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

Sequence in context: A089464 A111343 A302908 * A121397 A067369 A247249

Adjacent sequences: A187120 A187121 A187122 * A187124 A187125 A187126

Keyword

nonn

Author

Paul D. Hanna, Mar 08 2011

Status

approved