The base block is not counted among the n and must be the only block in the bottom layer of the building
Table of n, a(n) for n=1..9.
Cf. A112389, A123762 - A123827, A123829 - A123849.
Sequence in context: A286882 A326651 A055477 * A074815 A280122 A051622
Adjacent sequences: A123771 A123772 A123773 * A123775 A123776 A123777
Søren Eilers, Oct 29 2006