1,2
A has one hole, B has two, etc.
Equals A064529 - 1. Cf. A064531, A064532.
Sequence in context: A027652 A127282 A138954 * A037047 A118917 A204293
Adjacent sequences: A064527 A064528 A064529 * A064531 A064532 A064533
nonn,fini,full
N. J. A. Sloane (njas(AT)research.att.com), Oct 07 2001