1,2

Dr. Math, Source, about 2/3rds down. Message dated 01/18/2000.

Cf. A000330, A000537, A006003.

Sequence in context: A085367 A081267 A154560 this_sequence A048468 A048771 A055849

Adjacent sequences: A052150 A052151 A052152 this_sequence A052154 A052155 A052156

nonn

Tom Gray (TGray9278(AT)aol.com), Jan 24 2000

Better description from Larry Reeves (larryr(AT)acm.org), Mar 21 2001