4,3

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

Earl Glen Whitehead, Jr., Four-discordant permutations, J. Austral. Math. Soc. Ser. A 28 (1979), no. 3, 369-377.

Sequence in context: A159650 A092181 A001702 this_sequence A008663 A125334 A126492

Adjacent sequences: A004305 A004306 A004307 this_sequence A004309 A004310 A004311

nonn

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