A002875 Sorting numbers (see Motzkin article for details). (Formerly M1300 N0498)

1, 2, 4, 24, 128, 880, 7440

Offset

0,2

Comments

How is the sequence defined (see the links in A000262)? Also more terms would be welcome.

Based on the Motzkin article, where this sequence appears in the last row of the table on p. 173, one would expect that this sequence is the same as A294202. However, they seem to be unrelated. So the true definition of this sequence is a mystery. - Andrew Howroyd and Andrey Zabolotskiy, Oct 25 2017

References

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

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

Links

Table of n, a(n) for n=0..6.

Victor Meally, Comparison of several sequences given in Motzkin's paper "Sorting numbers for cylinders...", letter to N. J. A. Sloane, N. D.

T. S. Motzkin, Sorting numbers for cylinders and other classification numbers, in Combinatorics, Proc. Symp. Pure Math. 19, AMS, 1971, pp. 167-176. [Annotated, scanned copy]

OEIS Wiki, Sorting numbers

Index entries for sequences related to sorting

Crossrefs

Cf. A000262, A001861, A002872, A002873, A002874, A036073, A294201, A294202.

Sequence in context: A371892 A164313 A087981 * A330504 A330511 A110491

Adjacent sequences: A002872 A002873 A002874 * A002876 A002877 A002878

Keyword

nonn,unkn,more

Author

N. J. A. Sloane

Status

approved