1,3

a(13) <= 45 mentioned in Knuth, Sorting and Searching, Vol. 2. a(9) determined in 1991. - Ed Pegg Jr (ed(AT)mathpuzzle.com), Dec 05 2001

R. W. Floyd and D. E. Knuth, The Bose-Nelson sorting problem, pp. 163-172 of J. N. Srivastava, ed., A Survey of Combinatorial Theory, North-Holland, 1973.

H. Jullie, Lecture Notes in Comp. Sci. 929 (1995), 246-260.

D. E. Knuth, Art of Computer Programming, Vol. 3, Sect. 5.3.4, Eq. (11).

I. Parberry, "A Computer Assisted Optimal Depth Lower Bound for Nine-Input Sorting Networks", Mathematical Systems Theory, Vol. 24, pp. 101-116, 1991.

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

Ed Pegg Jr., Illustration of initial terms

J. H. Smith, Nine-Input Sorting Networks

Index entries for sequences related to sorting

A006282 is an upper bound. Cf. A036604.

Sequence in context: A120806 A020946 A091785 this_sequence A061562 A006282 A086845

Adjacent sequences: A003072 A003073 A003074 this_sequence A003076 A003077 A003078

hard,nonn,nice

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

Terms are exact for n<=9, otherwise the best known (according to Knuth).

Updates from Ed Pegg Jr (ed(AT)mathpuzzle.com), Dec 05 2001