1,1

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..8.

Cf. A112389, A123762 - A123827, A123829 - A123849.

Sequence in context: A116508 A055659 A218368 * A273921 A182607 A218284

Adjacent sequences: A123813 A123814 A123815 * A123817 A123818 A123819

nonn,hard

Søren Eilers, Oct 29 2006

approved