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..5.
Cf. A112389, A123762 - A123827, A123829 - A123849.
Sequence in context: A038531 A032910 A116235 * A265446 A145317 A251365
Adjacent sequences: A123811 A123812 A123813 * A123815 A123816 A123817
Søren Eilers, Oct 29 2006