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.

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A217325 Number of self-inverse permutations in S_n with longest increasing subsequence of length 5.

Original entry on oeis.org

1, 5, 29, 127, 583, 2446, 10484, 43363, 181546, 748840, 3114308, 12878441, 53594473, 222761422, 930856456, 3893811380, 16365678160, 68937445765, 291656714515, 1237403762663, 5271285939671, 22524961082326, 96620152734652, 415768621923904, 1795530067804295
Offset: 5

Views

Author

Alois P. Heinz, Sep 30 2012

Keywords

Comments

Also the number of Young tableaux with n cells and 5 rows.

Examples

			a(5) = 1: 12345.
a(6) = 5: 123465, 123546, 124356, 132456, 213456.
		

Crossrefs

Column k=5 of A047884.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<5, 0, `if`(n=5, 1,
         ((n+3)*(166075637*n^5+3319452867*n^4+10706068615*n^3-39910302747*n^2
           -182846631872*n-159926209260)*a(n-1) +(840221898216*n+133982123900
           -322021480097*n^3-83890810854*n^4+12016871251*n^5+3735622433*n^6
           +111397917411*n^2)*a(n-2)-(n-2)*(2142183361*n^5+66617759078*n^4
           -47640468971*n^3-611402096064*n^2+15449945364*n+452645243780)*a(n-3)
           -(n-2)*(n-3)*(33769818805*n^4-54918997862*n^3 -469629276839*n^2
           +789889969148*n +94438295920)*a(-4+n) -4*(n-2)*(n-3)*(-4+n)*
           (2060107324*n^3 -87569131518*n^2+293565842963*n -151080184425)*a(n-5)
           +240*(n-2)*(n-3)*(n-5)*(168175627*n-312397451)*(-4+n)^2*a(n-6))/
           (8*(13927136*n+37088781)*(n-5)*(n+6)*(n+4)*(n+3)^2)))
        end:
    seq(a(n), n=5..40);

Formula

a(n) = A182172(n,5) - A182172(n,4) = A049401(n) - A005817(n).

A217326 Number of self-inverse permutations in S_n with longest increasing subsequence of length 6.

Original entry on oeis.org

1, 6, 41, 209, 1106, 5323, 26069, 122901, 585922, 2747977, 13000269, 61088173, 289186846, 1366147708, 6496681304, 30905464864, 147912712795, 709073550307, 3418258506885, 16517431269189, 80230551304034, 390774361811783, 1912602871119956, 9388456361080840
Offset: 6

Views

Author

Alois P. Heinz, Sep 30 2012

Keywords

Comments

Also the number of Young tableaux with n cells and 6 rows.

Examples

			a(6) = 1: 123456.
a(7) = 6: 1234576, 1234657, 1235467, 1243567, 1324567, 2134567.
		

Crossrefs

Column k=6 of A047884.

Formula

a(n) = A182172(n,6)-A182172(n,5) = A007579(n)-A049401(n).

A217327 Number of self-inverse permutations in S_n with longest increasing subsequence of length 7.

Original entry on oeis.org

1, 7, 55, 319, 1904, 10275, 56135, 294386, 1556323, 8086433, 42298721, 219795160, 1149139210, 5999688692, 31506046052, 165664633982, 875886376212, 4643488263933, 24746018418741, 132328997879066, 711142850556217, 3836134976520394, 20791024498584110
Offset: 7

Views

Author

Alois P. Heinz, Sep 30 2012

Keywords

Comments

Also the number of Young tableaux with n cells and 7 rows.

Examples

			a(7) = 1: 1234567.
a(8) = 7: 12345687, 12345768, 12346578, 12354678, 12435678, 13245678, 21345678.
		

Crossrefs

Column k=7 of A047884.

Formula

a(n) = A182172(n,7)-A182172(n,6) = A007578(n)-A007579(n).

A217328 Number of self-inverse permutations in S_n with longest increasing subsequence of length 8.

Original entry on oeis.org

1, 8, 71, 461, 3057, 18225, 109446, 628652, 3628517, 20538209, 116808172, 659078098, 3737763884, 21153403644, 120354760098, 685455514294, 3925104616303, 22535893275064, 130089736567064, 753604985013128, 4388755545268226, 25660332309744370, 150802834643569274
Offset: 8

Views

Author

Alois P. Heinz, Sep 30 2012

Keywords

Comments

Also the number of Young tableaux with n cells and 8 rows.

Examples

			a(8) = 1: 12345678.
a(9) = 8: 123456798, 123456879, 123457689, 123465789, 123546789, 124356789, 132456789, 213456789.
		

Crossrefs

Column k=8 of A047884.

Formula

a(n) = A182172(n,8)-A182172(n,7) = A007580(n)-A007578(n).

A218262 Number of standard Young tableaux of n cells and height >= 10.

Original entry on oeis.org

1, 11, 121, 1001, 8086, 59228, 426673, 2946593, 20161558, 135303408, 904408398, 5995379358, 39727129830, 262629161094, 1739604051411, 11535387587595, 76763703224070, 512448824337780, 3436760740882050, 23151339236295810, 156789753069685500, 1067435349046248600
Offset: 10

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 >= 10.

Crossrefs

Column k=10 of A182222.

Formula

a(n) = A000085(n) - A212915(n) = A182172(n,n) - A182172(n,9).

A218263 Number of standard Young tableaux of n cells and height >= 3.

Original entry on oeis.org

1, 4, 16, 56, 197, 694, 2494, 9244, 35234, 139228, 566788, 2387048, 10343101, 46193866, 211775002, 997265204, 4809609062, 23758479340, 119952340180, 618883933480, 3257842530546, 17492187873444, 95680438560276, 532985197799976, 3020676725917252
Offset: 3

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 >= 3. a(3)=1: 123; a(4)=4: 1234, 1243, 1324, 2134.

Crossrefs

Column k=3 of A182222.

Programs

  • Maple
    b:= proc(n) b(n):= `if`(n<2, 1, b(n-1) +(n-1)*b(n-2)) end:
    a:= n-> b(n) -binomial(n, iquo(n, 2)):
    seq(a(n), n=3..30);
  • Mathematica
    b[n_] := b[n] = If[n<2, 1, b[n-1] + (n-1)*b[n-2]];
    a[n_] := b[n] - Binomial[n, Quotient[n, 2]];
    Table[a[n], {n, 3, 30}] (* Jean-François Alcover, Aug 23 2021, after Alois P. Heinz *)

Formula

a(n) = A000085(n) - A001405(n) = A182172(n,n) - A182172(n,2).
Conjecture: (n-6)*(n-3)*(n+1)*a(n) +(-n^3+6*n^2+11*n-36)*a(n-1) -(n-1)*(n^3-4*n^2-21*n+76)*a(n-2) +2*(n-1)*(n-2)*(3*n-19)*a(n-3) +4*(n-5)*(n-1)*(n-2)*(n-3)*a(n-4)=0. - R. J. Mathar, Jan 04 2017

A218264 Number of standard Young tableaux of n cells and height >= 4.

Original entry on oeis.org

1, 5, 25, 105, 441, 1785, 7308, 29898, 124641, 526669, 2276846, 10038964, 45353269, 209442533, 990777442, 4791502156, 23707812077, 119810145337, 618483875689, 3256714122209, 17488997849803, 95671400358075, 532959538382100, 3020603738202750, 17411069344112895
Offset: 4

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 >= 4. a(4)=1: 1234; a(5)=5: 12345, 12354, 12435, 13245, 21345.

Crossrefs

Column k=4 of A182222.

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<5, [0$4, 1][n+1], ((-5-7*n+3*n^2)*a(n-1)
            +(n-1)*(n^2-n-11)*a(n-2) -2*n*(n-1)*(n-2)*a(n-3)
            -3*(n-1)*(n-2)*(n-3)*a(n-4))/((n+2)*(n-4)))
        end:
    seq(a(n), n=4..30);
  • Mathematica
    a[n_] := a[n] = If[n<5, {0,0,0,0,1}[[n+1]], ((-5-7n+3n^2)a[n-1] + (n-1)(n^2-n-11)a[n-2] - 2n(n-1)(n-2)a[n-3] - 3(n-1)(n-2)(n-3)a[n-4])/ ((n+2)(n-4))];
    Table[a[n], {n, 4, 30}] (* Jean-François Alcover, Aug 23 2021, after Alois P. Heinz *)

Formula

a(n) = A000085(n) - A001006(n) = A182172(n,n) - A182172(n,3).

A218265 Number of standard Young tableaux of n cells and height >= 5.

Original entry on oeis.org

1, 6, 36, 176, 856, 3952, 18272, 83524, 384463, 1777010, 8304636, 39254076, 188160268, 915651672, 4527595824, 22771294440, 116496899100, 606656445480, 3214574890480, 17337658462800, 95128543350576, 530998366724576, 3013524116661952, 17385349086129304
Offset: 5

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 >= 5. a(5)=1: 12345; a(6)=6: 123456, 123465, 123546, 124356, 132456, 213456.

Crossrefs

Column k=5 of A182222.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<13,
          [0$5, 1, 6, 36, 176, 856, 3952, 18272, 83524][n+1],
          ((n^4-2*n^3-179*n^2+256*n+804) *a(n-1)
          +(n-1)*(n^4+6*n^3-295*n^2+1108*n+100) *a(n-2)
          -4*(n-1)*(n-2)*(6*n^2-83*n+67) *a(n-3)
          -16*(n-11)*(n-1)*(n-3)*(n-2)^2 *a(n-4))/
          ((n-12)*(n-5)*(n+4)*(n+3)))
        end:
    seq(a(n), n=5..30);

Formula

a(n) = A000085(n) - A005817(n) = A182172(n,n) - A182172(n,4).

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

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 >= 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).

A218267 Number of standard Young tableaux of n cells and height >= 7.

Original entry on oeis.org

1, 8, 64, 400, 2465, 14092, 80016, 442248, 2442351, 13375366, 73477622, 403703404, 2230591660, 12380801756, 69225756076, 389806286920, 2213844625658, 12681996193252, 73339826141716, 428242854338216, 2526129602115517, 15056977593085444, 90712249806247400
Offset: 7

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 >= 7. a(7)=1: 1234567; a(8)=8: 12345678, 12345687, 12345768, 12346578, 12354678, 12435678, 13245678, 21345678.

Crossrefs

Column k=7 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], ((20*n^2+184*n+336)*g(n-1)
           +4*(n-1)*(10*n^2+58*n+33)*g(n-2) -144*(n-1)*(n-2)*g(n-3)
           -144*(n-1)*(n-2)*(n-3)*g(n-4)) / ((n+5)*(n+8)*(n+9)))
        end:
    a:= n-> b(n) -g(n):
    seq(a(n), n=7..30);

Formula

a(n) = A000085(n) - A007579(n) = A182172(n,n) - A182172(n,6).
Previous Showing 31-40 of 43 results. Next