cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A218266 Number of standard Young tableaux of n cells and height >= 6.

Original entry on oeis.org

1, 7, 49, 273, 1506, 7788, 40161, 202917, 1028170, 5190328, 26375635, 134565795, 692890250, 3596739368, 18877483060, 100131220940, 537718999715, 2922918175965, 16100254700137, 89857257410905, 508473405642250, 2916903963927300, 16969580464205400
Offset: 6

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Author

Alois P. Heinz, Oct 24 2012

Keywords

Comments

Also number of self-inverse permutations in S_n with longest increasing subsequence of length >= 6. a(6)=1: 123456; a(7)=7: 1234567, 1234576, 1234657, 1235467, 1243567, 1324567, 2134567.

Crossrefs

Column k=6 of A182222.

Programs

  • Maple
    b:= proc(n) b(n):= `if`(n<2, 1, b(n-1) +(n-1)*b(n-2)) end:
    g:= proc(n) option remember; `if`(n<3, [1, 1, 2][n+1],
          ((3*n^2+17*n+15)*g(n-1) +(n-1)*(13*n+9)*g(n-2)
           -15*(n-1)*(n-2)*g(n-3)) / ((n+4)*(n+6)))
        end:
    a:= n-> b(n) -g(n):
    seq(a(n), n=6..30);

Formula

a(n) = A000085(n) - A049401(n) = A182172(n,n) - A182172(n,5).