1,9
Table of n, a(n) for n=1..30.
Joseph Myers, Polyomino tiling
Sequence in context: A061240 A062341 A176251 * A222088 A146467 A053518
Adjacent sequences: A121305 A121306 A121307 * A121309 A121310 A121311
nonn
N. J. A. Sloane, Aug 25 2006
Adjusted to offset 1 and a(29) and a(30) added by Joseph Myers, Nov 21 2010
approved