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.

Previous Showing 41-43 of 43 results.

A218268 Number of standard Young tableaux of n cells and height >= 8.

Original entry on oeis.org

1, 9, 81, 561, 3817, 23881, 147862, 886028, 5288933, 31178901, 183908244, 1081452450, 6381113064, 37719710024, 224141652938, 1337958249446, 8038507929319, 48593807722975, 295913856459150, 1814986751559300, 11220842616565050, 69921225307663290
Offset: 8

Views

Author

Alois P. Heinz, Oct 24 2012

Keywords

Comments

Also number of self-inverse permutations in S_n with longest increasing subsequence of length >= 8. a(8)=1: 12345678; a(9)=9: 123456789, 123456798, 123456879, 123457689, 123465789, 123546789, 124356789, 132456789, 213456789.

Crossrefs

Column k=8 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<4, [1, 1, 2, 4][n+1],
          ((4*n^3+78*n^2+424*n+495)*g(n-1) +(n-1)*(34*n^2+280*n
          +305)*g(n-2) -2*(n-1)*(n-2)*(38*n+145)*g(n-3) -105*(n-1)
          *(n-2)*(n-3)*g(n-4)) / ((n+6)*(n+10)*(n+12)))
        end:
    a:= n-> b(n) -g(n):
    seq(a(n), n=8..30);

Formula

a(n) = A000085(n) - A007578(n) = A182172(n,n) - A182172(n,7).

A218269 Number of standard Young tableaux of n cells and height >= 9.

Original entry on oeis.org

1, 10, 100, 760, 5656, 38416, 257376, 1660416, 10640692, 67100072, 422374352, 2643349180, 16566306380, 103786892840, 652502735152, 4113403313016, 26057914447911, 165824119892086, 1061381766546172, 6832087071296824, 44260892997918920, 288574772339715376
Offset: 9

Views

Author

Alois P. Heinz, Oct 24 2012

Keywords

Comments

Also number of self-inverse permutations in S_n with longest increasing subsequence of length >= 9.

Crossrefs

Column k=9 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<4, [1, 1, 2, 4][n+1],
          ((40*n^3+1084*n^2+8684*n+18480)*g(n-1) +16*(n-1)
          *(5*n^3+107*n^2+610*n+600)*g(n-2) -1024*(n-1)*(n-2)
          *(n+6)*g(n-3) -1024*(n-1)*(n-2)*(n-3)*(n+4)*g(n-4))/
           ((n+7)*(n+12)*(n+15)*(n+16)))
        end:
    a:= n-> b(n) -g(n):
    seq(a(n), n=9..30);

Formula

a(n) = A000085(n) - A007580(n) = A182172(n,n) - A182172(n,8).

A229068 Number of standard Young tableaux of n cells and height <= 12.

Original entry on oeis.org

1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, 35696, 140152, 568503, 2390466, 10349340, 46204720, 211779200, 997134592, 4808141824, 23745792032, 119848119307, 618058083314, 3251373425356, 17442275104496, 95297400355320, 530067682582320, 2998503402985440
Offset: 0

Views

Author

Vaclav Kotesovec, Sep 12 2013

Keywords

Comments

Conjecture: generally (for tableaux with height <= k), a(n) ~ k^n/Pi^(k/2) * (k/n)^(k*(k-1)/4) * Product_{j=1..k} Gamma(j/2); set k=12 for this sequence.

Crossrefs

Cf. A182172, A001405 (k=2), A001006 (k=3), A005817 (k=4), A049401 (k=5), A007579 (k=6), A007578 (k=7), A007580 (k=8), A212915 (k=9), A212916 (k=10), A229053 (k=11).
Column k=12 of A182172.

Programs

  • Mathematica
    RecurrenceTable[{-147456 (-5+n) (-4+n) (-3+n) (-2+n) (-1+n) (12+n) a[-6+n]-110592 (-4+n) (-3+n) (-2+n) (-1+n) (29+2 n) a[-5+n]+256 (-3+n) (-2+n) (-1+n) (121272+32786 n+2343 n^2+49 n^3) a[-4+n]+128 (-2+n) (-1+n) (438597+90321 n+5391 n^2+98 n^3) a[-3+n]-16 (-1+n) (8718630+5347213 n+804616 n^2+49754 n^3+1372 n^4+14 n^5) a[-2+n]-8 (27335490+10162354 n+1206473 n^2+63328 n^3+1533 n^4+14 n^5) a[-1+n]+(11+n) (20+n) (27+n) (32+n) (35+n) (36+n) a[n]==0, a[1]==1, a[2]==2, a[3]==4, a[4]==10, a[5]==26, a[6]==76}, a, {n, 20}]

Formula

Recurrence: (n+11)*(n+20)*(n+27)*(n+32)*(n+35)*(n+36)*a(n) = 8*(14*n^5 + 1533*n^4 + 63328*n^3 + 1206473*n^2 + 10162354*n + 27335490)*a(n-1) + 16*(n-1)*(14*n^5 + 1372*n^4 + 49754*n^3 + 804616*n^2 + 5347213*n + 8718630)*a(n-2) - 128*(n-2)*(n-1)*(98*n^3 + 5391*n^2 + 90321*n + 438597)*a(n-3) - 256*(n-3)*(n-2)*(n-1)*(49*n^3 + 2343*n^2 + 32786*n + 121272)*a(n-4) + 110592*(n-4)*(n-3)*(n-2)*(n-1)*(2*n + 29)*a(n-5) + 147456*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(n+12)*a(n-6).
a(n) ~ 602791875/128 * 12^(n+33)/(Pi^3*n^33).
Previous Showing 41-43 of 43 results.