1,2

a(n)=(1/6)*(57*n^3-81*n^2+30*n)

Cf. A100164 = alternate vertex; A100145 for more on structured numbers.

Sequence in context: A097199 A100165 A100173 this_sequence A124998 A126419 A035286

Adjacent sequences: A100169 A100170 A100171 this_sequence A100173 A100174 A100175

easy,nonn

James A. Record (james.record(AT)gmail.com). Nov 07, 2004.