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 11-16 of 16 results.

A285233 Number of entries in the fifth cycles of all permutations of [n].

Original entry on oeis.org

1, 17, 221, 2724, 34009, 441383, 6020276, 86673088, 1318681308, 21194234508, 359421505224, 6421154849208, 120637782989568, 2379195625677696, 49167226489281408, 1062833010282628992, 23992442301958329600, 564697104190192569600, 13836823816466433139200
Offset: 5

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=5 of A185105.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<6, [0$5, 1][n+1],
          ((4*(n^3-9*n^2+24*n-19))*a(n-1)-(6*n^4-72*n^3+
           307*n^2-547*n+334)*a(n-2)+(4*n^5-64*n^4+398*n^3
          -1191*n^2+1683*n-862)*a(n-3)-(n-4)^5*(n-1)*a(n-4))
          /((n-2)*(n-5)))
        end:
    seq(a(n), n=5..25);
  • Mathematica
    a[3] = a[4] = 0; a[5] = 1; a[6] = 17; a[n_] := a[n] = ((4(n^3 - 9n^2 + 24n - 19)) a[n-1] - (6n^4 - 72n^3 + 307n^2 - 547n + 334) a[n-2] + (4n^5 - 64n^4 + 398n^3 - 1191n^2 + 1683n - 862) a[n-3] - (n-4)^5 (n-1) a[n-4]) / ((n - 2)(n - 5));
    Table[a[n], {n, 5, 25}] (* Jean-François Alcover, Jun 01 2018, from Maple *)

Formula

a(n) = A185105(n,5).
a(n) ~ n!*n/32. - Vaclav Kotesovec, Apr 25 2017

A285234 Number of entries in the sixth cycles of all permutations of [n].

Original entry on oeis.org

1, 23, 382, 5780, 86029, 1301673, 20338679, 330737236, 5618265376, 99849949772, 1857170751804, 36135886878072, 734947859916792, 15608257104179952, 345724111468700496, 7977315239656638912, 191516062334747746752, 4778050475554642998144, 123731984754223222096512
Offset: 6

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=6 of A185105.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<7, [0$6, 1][n+1],
          ((5*n^3-58*n^2+207*n-230)*a(n-1)-(10*n^4-152*n^3
           +835*n^2-1973*n+1690)*a(n-2)+(n-4)*(10*n^4
           -158*n^3+909*n^2-2251*n+2000)*a(n-3)-(5*n^6
           -127*n^5+1330*n^4-7335*n^3+22396*n^2-35717*n
           +23058)*a(n-4)+(n-5)^6*(n-2)*a(n-5))/((n-3)*(n-6)))
        end:
    seq(a(n), n=6..25);
  • Mathematica
    b[n_, i_] := b[n, i] = Expand[If[n==0, 1, Sum[Function[p, p + Coefficient[ p, x, 0]*j*x^i][b[n-j, i+1]]*Binomial[n-1, j-1]*(j-1)!, {j, 1, n}]]];
    a[n_] := Function[p, Table[Coefficient[p, x, i], {i, 1, n}]][b[n, 1]][[6]];
    Table[a[n], {n, 6, 25}] (* Jean-François Alcover, Jun 01 2018, after Alois P. Heinz *)

Formula

a(n) = A185105(n,6).
a(n) ~ n!*n/64. - Vaclav Kotesovec, Apr 25 2017

A285235 Number of entries in the seventh cycles of all permutations of [n].

Original entry on oeis.org

1, 30, 622, 11378, 199809, 3499572, 62333543, 1141073295, 21593291506, 423749322362, 8637159909596, 182967605341204, 4028364756058464, 92147187469290768, 2188667860854515856, 53939340317601471888, 1378181549321980128288, 36476226109960185948768
Offset: 7

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=7 of A185105.

Programs

  • Maple
    b:= proc(n, i) option remember; expand(`if`(n=0, 1,
          add((p-> p+`if`(i=1, coeff(p, x, 0)*j*x, 0))(
          b(n-j, max(0, i-1)))*binomial(n-1, j-1)*
          (j-1)!, j=1..n)))
        end:
    a:= n-> coeff(b(n, 7), x, 1):
    seq(a(n), n=7..30);
  • Mathematica
    b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, Sum[Function[p, p + If[i == 1, Coefficient[p, x, 0]*j*x, 0]][b[n - j, Max[0, i - 1]]]*Binomial[n - 1, j - 1]*(j - 1)!, {j, 1, n}]]];
    a[n_] := Coefficient[b[n, 7], x, 1];
    Table[a[n], {n, 7, 30}] (* Jean-François Alcover, Jun 01 2018, from Maple *)

Formula

a(n) = A185105(n,7).
Recurrence: (n-7)*(n-4)*a(n) = (n-3)*(6*n^2 - 67*n + 176)*a(n-1) - 5*(n-4)*(3*n^3 - 43*n^2 + 195*n - 283)*a(n-2) + 10*(2*n^5 - 47*n^4 + 436*n^3 - 1999*n^2 + 4532*n - 4062)*a(n-3) - (15*n^6 - 445*n^5 + 5465*n^4 - 35555*n^3 + 129161*n^2 - 248111*n + 196528)*a(n-4) + (6*n^7 - 221*n^6 + 3473*n^5 - 30165*n^4 + 156251*n^3 - 482105*n^2 + 819087*n - 589808)*a(n-5) - (n-6)^7*(n-3)*a(n-6), for n>7. - Vaclav Kotesovec, Apr 25 2017
a(n) ~ n!*n/128. - Vaclav Kotesovec, Apr 25 2017

A285236 Number of entries in the eighth cycles of all permutations of [n].

Original entry on oeis.org

1, 38, 964, 21018, 431007, 8671656, 175065071, 3591984289, 75473055841, 1631318215818, 36369569578502, 837619857754240, 19943142053389024, 491010028537071248, 12499878460133012064, 328936666440527737296, 8943724877454118086096, 251125623168859020015072
Offset: 8

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=8 of A185105.

Programs

  • Maple
    b:= proc(n, i) option remember; expand(`if`(n=0, 1,
          add((p-> p+`if`(i=1, coeff(p, x, 0)*j*x, 0))(
          b(n-j, max(0, i-1)))*binomial(n-1, j-1)*
          (j-1)!, j=1..n)))
        end:
    a:= n-> coeff(b(n, 8), x, 1):
    seq(a(n), n=8..30);
  • Mathematica
    b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, Sum[Function[p, p + If[i == 1, Coefficient[p, x, 0]*j*x, 0]][b[n - j, Max[0, i - 1]]]*Binomial[n - 1, j - 1]*(j - 1)!, {j, 1, n}]]];
    a[n_] := Coefficient[b[n, 8], x, 1];
    Table[a[n], {n, 8, 30}] (* Jean-François Alcover, Jun 01 2018, from Maple *)

Formula

a(n) = A185105(n,8).
Recurrence: (n-8)*(n-5)*a(n) = (7*n^3 - 117*n^2 + 618*n - 1036)*a(n-1) - (21*n^4 - 450*n^3 + 3521*n^2 - 11996*n + 15092)*a(n-2) + 5*(7*n^5 - 190*n^4 + 2039*n^3 - 10842*n^2 + 28614*n - 30016)*a(n-3) - (35*n^6 - 1185*n^5 + 16635*n^4 - 124015*n^3 + 518011*n^2 - 1149493*n + 1058400)*a(n-4) + (n-6)*(21*n^6 - 747*n^5 + 11033*n^4 - 86597*n^3 + 380805*n^2 - 888917*n + 859586)*a(n-5) - (7*n^8 - 352*n^7 + 7728*n^6 - 96726*n^5 + 754656*n^4 - 3756732*n^3 + 11646888*n^2 - 20547489*n + 15780868)*a(n-6) + (n-7)^8*(n-4)*a(n-7), for n>8. - Vaclav Kotesovec, Apr 25 2017
a(n) ~ n!*n/256. - Vaclav Kotesovec, Apr 25 2017

A285237 Number of entries in the ninth cycles of all permutations of [n].

Original entry on oeis.org

1, 47, 1434, 36792, 872511, 20014299, 455265257, 10420963144, 242208466145, 5748862140283, 139849088103596, 3494752531722564, 89838192687840304, 2377612074981717632, 64807344109730799968, 1819505580964336136560, 52611858820598185363536
Offset: 9

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=9 of A185105.

Programs

  • Maple
    b:= proc(n, i) option remember; expand(`if`(n=0, 1,
          add((p-> p+`if`(i=1, coeff(p, x, 0)*j*x, 0))(
          b(n-j, max(0, i-1)))*binomial(n-1, j-1)*
          (j-1)!, j=1..n)))
        end:
    a:= n-> coeff(b(n, 9), x, 1):
    seq(a(n), n=9..30);
  • Mathematica
    b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, Sum[Function[p, p + If[i == 1, Coefficient[p, x, 0]*j*x, 0]][b[n - j, Max[0, i - 1]]]*Binomial[n - 1, j - 1]*(j - 1)!, {j, 1, n}]]];
    a[n_] := Coefficient[b[n, 9], x, 1];
    Table[a[n], {n, 9, 30}] (* Jean-François Alcover, Jun 01 2018, from Maple *)

Formula

a(n) = A185105(n,9).
Recurrence: (n-9)*(n-6)*a(n) = 2*(4*n^3 - 77*n^2 + 471*n - 916)*a(n-1) - 14*(2*n^4 - 49*n^3 + 439*n^2 - 1714*n + 2474)*a(n-2) + 14*(n-5)*(4*n^4 - 103*n^3 + 981*n^2 - 4117*n + 6454)*a(n-3) - 7*(n-6)*(10*n^5 - 320*n^4 + 4070*n^3 - 25770*n^2 + 81333*n - 102427)*a(n-4) + 14*(4*n^7 - 185*n^6 + 3661*n^5 - 40195*n^4 + 264477*n^3 - 1042986*n^2 + 2282488*n - 2138058)*a(n-5) - (28*n^8 - 1554*n^7 + 37702*n^6 - 522242*n^5 + 4517128*n^4 - 24979724*n^3 + 86233855*n^2 - 169871843*n + 146155098)*a(n-6) + (8*n^9 - 526*n^8 + 15356*n^7 - 261226*n^6 + 2853242*n^5 - 20747608*n^4 + 100420076*n^3 - 311890495*n^2 + 563892963*n - 452026202)*a(n-7) - (n-8)^9*(n-5)*a(n-8), for n>9. - Vaclav Kotesovec, Apr 25 2017
a(n) ~ n!*n/512. - Vaclav Kotesovec, Apr 25 2017

A285238 Number of entries in the tenth cycles of all permutations of [n].

Original entry on oeis.org

1, 57, 2061, 61524, 1672323, 43426821, 1106667572, 28127644296, 720378419177, 18715673685469, 495446888127507, 13403690294272704, 371315688867567088, 10546557230068193568, 307378160401299252032, 9196581430595518185328, 282526394585486139996736
Offset: 10

Views

Author

Alois P. Heinz, Apr 15 2017

Keywords

Comments

Each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.

Crossrefs

Column k=10 of A185105.

Programs

  • Maple
    b:= proc(n, i) option remember; expand(`if`(n=0, 1,
          add((p-> p+`if`(i=1, coeff(p, x, 0)*j*x, 0))(
          b(n-j, max(0, i-1)))*binomial(n-1, j-1)*
          (j-1)!, j=1..n)))
        end:
    a:= n-> coeff(b(n, 10), x, 1):
    seq(a(n), n=10..30);
  • Mathematica
    b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, Sum[Function[p, p + If[i == 1, Coefficient[p, x, 0]*j*x, 0]][b[n - j, Max[0, i - 1]]]*Binomial[n - 1, j - 1]*(j - 1)!, {j, 1, n}]]];
    a[n_] := Coefficient[b[n, 10], x, 1];
    Table[a[n], {n, 10, 30}] (* Jean-François Alcover, Jun 01 2018, from Maple *)

Formula

a(n) = A185105(n,10).
Recurrence: (n-10)*(n-7)*a(n) = (9*n^3 - 196*n^2 + 1361*n - 3006)*a(n-1) - 2*(18*n^4 - 496*n^3 + 5001*n^2 - 21971*n + 35682)*a(n-2) + 14*(6*n^5 - 206*n^4 + 2797*n^3 - 18829*n^2 + 63002*n - 83988)*a(n-3) - 7*(18*n^6 - 758*n^5 + 13240*n^4 - 122950*n^3 + 640883*n^2 - 1779393*n + 2057142)*a(n-4) + 7*(18*n^7 - 916*n^6 + 19950*n^5 - 241180*n^4 + 1748577*n^3 - 7604998*n^2 + 18375843*n - 19031658)*a(n-5) - (84*n^8 - 5096*n^7 + 135226*n^6 - 2050286*n^5 + 19428976*n^4 - 117838826*n^3 + 446719463*n^2 - 967742093*n + 917171710)*a(n-6) + (n-8)*(36*n^8 - 2284*n^7 + 63390*n^6 - 1005202*n^5 + 9960732*n^4 - 63153820*n^3 + 250166217*n^2 - 565970839*n + 559792740)*a(n-7) - (9*n^10 - 749*n^9 + 28038*n^8 - 621666*n^7 + 9040584*n^6 - 90096090*n^5 + 623077092*n^4 - 2952338109*n^3 + 9171809128*n^2 - 16867010733*n + 13941384550)*a(n-8) + (n-9)^10*(n-6)*a(n-9), for n>10. - Vaclav Kotesovec, Apr 25 2017
a(n) ~ n!*n/1024. - Vaclav Kotesovec, Apr 25 2017
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