4,2

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

Baer, R. M.; Brock, P.; Natural sorting over permutation spaces. Math. Comp. 22 1968 385-410.

J. M. Hammersley, A few seedings of research, in Proc. Sixth Berkeley Sympos. Math. Stat. and Prob., ed. L. M. le Cam et al., Univ. Calif. Press, 1972, Vol. I, pp. 345-394.

A row of A047874.

Sequence in context: A021084 A016305 A016909 this_sequence A016298 A125428 A016249

Adjacent sequences: A001452 A001453 A001454 this_sequence A001456 A001457 A001458

nonn

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