0,2

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).

T. S. Motzkin, Sorting numbers ...: for a link to this paper see A000262.

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

T. D. Noe, Table of n, a(n) for n=0..100

Index entries for sequences related to sorting

E.g.f.: exp (( exp(3*x) - 4) / 3 + exp(x) ).

u[0, j_]:=1; u[k_, j_]:=u[k, j]=Sum[Binomial[k-1, i-1]Plus@@(u[k-i, j]#^(i-1)&/@Divisors[j]), {i, k}]; Table[u[n, 3], {n, 0, 12}] [From Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 06 2008]

u[n,j] generates for j=1, A000110 Bell numbers; j=2, A002872 "Sorting numbers"; j=3, A002874 "Sorting numbers"; j=4, A141003 (Mathar); j=5, A036075 "Sorting numbers"; j=6, A141004 (Mathar); j=7, A036077 "Sorting numbers" [From Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 06 2008]

Sequence in context: A054993 A005315 A121635 this_sequence A078592 A052646 A002856

Adjacent sequences: A002871 A002872 A002873 this_sequence A002875 A002876 A002877

nonn,easy,nice

N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)