1,2

a(n)=(1/6)*(22*n^3-24*n^2+8*n)

Cf. A063521 = alternate vertex; A100188 = structured anti-diamonds; A100145 for more on structured numbers.

Sequence in context: A043153 A039330 A043933 this_sequence A005906 A036660 A063493

Adjacent sequences: A100183 A100184 A100185 this_sequence A100187 A100188 A100189

easy,nonn

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