0,3

a(3)=17 since can map (1,2,3) to (1,1,1), (1,1,2), (1,1,3), (1,2,2), (1,2,3), (1,3,3), (2,1,1), (2,2,1), (2,2,2), (2,2,3), (2,3,3), (3,1,1), (3,2,1), (3,2,2), (3,3,1), (3,3,2), or (3,3,3) but not for example to (1,3,2)

Cf. A000312, A000984, A001700.

Sequence in context: A005784 A095252 A102207 this_sequence A046723 A030529 A081113

Adjacent sequences: A045989 A045990 A045991 this_sequence A045993 A045994 A045995

nonn

N. J. A. Sloane (njas(AT)research.att.com).