1,1

Or, numbers in which the number of distinct base 4 digits is 4.

Sequence in context: A033395 A143754 A023146 this_sequence A049355 A095585 A095571

Adjacent sequences: A031942 A031943 A031944 this_sequence A031946 A031947 A031948

nonn,base

Clark Kimberling (ck6(AT)evansville.edu)

Edited by N. J. A. Sloane, Apr 05 2009 at the suggestion of R. J. Mathar