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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A245795 Number of preferential arrangements of n labeled elements when at least k=10 elements per rank are required.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 184757, 705433, 1998725, 4992289, 11618957, 25852921, 55791791, 117832681, 245039011, 503891821, 5552024604991, 46933238932021, 261680950107511, 1205121760579981, 4959685199012641, 18947093053200193
Offset: 0

Views

Author

Alois P. Heinz, Aug 01 2014

Keywords

Crossrefs

Cf. column k=10 of A245732.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n=0, 1,
           add(a(n-j)*binomial(n, j), j=10..n))
        end:
    seq(a(n), n=0..40);
  • Mathematica
    CoefficientList[Series[1/(2 + x - E^x + x^2/2! + x^3/3! + x^4/4! + x^5/5! + x^6/6! + x^7/7! + x^8/8! + x^9/9!),{x,0,40}],x]*Range[0,40]! (* Vaclav Kotesovec, Aug 02 2014 *)

Formula

E.g.f.: 1/(2 + x - exp(x) + x^2/2! + x^3/3! + x^4/4! + x^5/5! + x^6/6! + x^7/7! + x^8/8! + x^9/9!). - Vaclav Kotesovec, Aug 02 2014
a(n) ~ n! / ((1+r^9/9!) * r^(n+1)), where r = 4.320434975980068857383128... is the root of the equation 2 + r - exp(r) + r^2/2! + r^3/3! + r^4/4! + r^5/5! + r^6/6! + r^7/7! + r^8/8! + r^9/9! = 0. - Vaclav Kotesovec, Aug 02 2014

A245854 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 1.

Original entry on oeis.org

1, 2, 12, 68, 520, 4542, 46550, 540136, 7045020, 101865410, 1619046418, 28053492348, 526430246264, 10636085523910, 230214619661790, 5314695463338704, 130356558777712468, 3385311352838750538, 92797887464933030762, 2677623216872061223780, 81123642038690958720048
Offset: 1

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=1 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 1) -b(n, 2):
    seq(a(n), n=1..25);
  • Mathematica
    With[{nn=30},CoefficientList[Series[1/(2-Exp[x])-1/(2-Exp[x]+x),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jul 29 2024 *)

Formula

E.g.f.: 1/(2-exp(x))-1/(2-exp(x)+x).
a(n) = A000670(n) - A032032(n) = A245732(n,1) - A245732(n,2).

A245855 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 2.

Original entry on oeis.org

1, 0, 6, 20, 120, 672, 5516, 40140, 368640, 3521870, 37445298, 422339502, 5215454426, 68144100780, 954428684280, 14160968076584, 222769496190060, 3692874342747114, 64493471050666430, 1181830474135532130, 22692074431844298558, 455404848204906308984
Offset: 2

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=2 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 2) -b(n, 3):
    seq(a(n), n=2..25);

Formula

E.g.f.: 1/(2-exp(x)+x) -1/(2-exp(x)+x+x^2/2).
a(n) = A032032(n) - A102233(n) = A245732(n,2) - A245732(n,3).

A245856 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 3.

Original entry on oeis.org

1, 0, 0, 20, 70, 112, 1848, 12840, 62700, 591800, 5484908, 40589276, 421291780, 4704380800, 46345716880, 533446290384, 6931113219780, 85313661653400, 1121432682942740, 16310909250477380, 237534778732260548, 3578871132644512672, 57980168196079811800
Offset: 3

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=3 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 3) -b(n, 4):
    seq(a(n), n=3..30);
  • Mathematica
    With[{nn=30},CoefficientList[Series[1/(2-Exp[x]+x+x^2/2)-1/(2-Exp[x]+ x+ x^2/2+ x^3/6),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Feb 14 2016 *)

Formula

E.g.f.: 1/(2-exp(x)+x+x^2/2)-1/(2-exp(x)+x+x^2/2+x^3/6).
a(n) = A102233(n) - A232475(n) = A245732(n,3) - A245732(n,4).

A245857 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 4.

Original entry on oeis.org

1, 0, 0, 0, 70, 252, 420, 660, 35640, 271700, 1389388, 5137860, 79463020, 905649500, 7336909980, 48400150764, 573924746400, 7735300382250, 85942063340210, 795156908528290, 9670781421636258, 143772253669334950, 1993964186469438950, 24015169625528033550
Offset: 4

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=4 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 4) -b(n, 5):
    seq(a(n), n=4..30);

Formula

E.g.f.: 1/(1-Sum_{j>=4} x^j/j!) - 1/(1-Sum_{j>=5} x^j/j!).
a(n) = A232475(n) - A245790(n) = A245732(n,4) - A245732(n,5).

A245858 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 5.

Original entry on oeis.org

1, 0, 0, 0, 0, 252, 924, 1584, 2574, 4004, 762762, 6062784, 31868200, 121314312, 399096216, 12936646128, 167685283332, 1429020461484, 9754485257594, 55756633204272, 905519956068420, 14816352889289380, 179362257853420980, 1745771827872126600
Offset: 5

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=5 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 5) -b(n, 6):
    seq(a(n), n=5..30);

Formula

E.g.f.: 1/(1-Sum_{j>=5} x^j/j!) - 1/(1-Sum_{j>=6} x^j/j!).
a(n) = A245790(n) - A245791(n) = A245732(n,5) - A245732(n,6).

A245859 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 6.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 924, 3432, 6006, 10010, 16016, 24752, 17190264, 139729800, 748339320, 2910015528, 9794896188, 30251595066, 2396910064472, 33228482071400, 291616291666700, 2036218597884900, 11895959650285620, 61536913327513260, 1662981928016982300
Offset: 6

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=6 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 6) -b(n, 7):
    seq(a(n), n=6..35);

Formula

E.g.f.: 1/(1-Sum_{j>=6} x^j/j!) - 1/(1-Sum_{j>=7} x^j/j!).
a(n) = A245791(n) - A245792(n) = A245732(n,6) - A245732(n,7).

A245860 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 7.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 3432, 12870, 22880, 38896, 63648, 100776, 155040, 399305520, 3292693008, 17879790324, 70676513424, 242216077400, 762341522800, 2264840592300, 478970960616720, 6869326015894680, 61426122596911800, 435982960069722000, 2589856033041531072
Offset: 7

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=7 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 7) -b(n, 8):
    seq(a(n), n=7..35);

Formula

E.g.f.: 1/(1-Sum_{j>=7} x^j/j!) - 1/(1-Sum_{j>=8} x^j/j!).
a(n) = A245792(n) - A245793(n) = A245732(n,7) - A245732(n,8).

A245861 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 8.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 12870, 48620, 87516, 151164, 251940, 406980, 639540, 980628, 9466982712, 78881427900, 432962644400, 1733914096200, 6029537213700, 19273224716460, 58178097911700, 168431757261300, 100033451495909100, 1461521434059544572
Offset: 8

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=8 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 8) -b(n, 9):
    seq(a(n), n=8..35);

Formula

E.g.f.: 1/(1-Sum_{j>=8} x^j/j!) - 1/(1-Sum_{j>=9} x^j/j!).
a(n) = A245793(n) - A245794(n) = A245732(n,8) - A245732(n,9).

A245862 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 9.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 48620, 184756, 335920, 587860, 994840, 1634380, 2615008, 4085950, 6249100, 227882805150, 1914150638400, 10597377540750, 42894094729200, 150967391072550, 488846715676800, 1495608303532200, 4389524294884872, 12479799500904120
Offset: 9

Views

Author

Alois P. Heinz, Aug 04 2014

Keywords

Crossrefs

Column k=9 of A245733.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(n, j), j=k..n))
        end:
    a:= n-> b(n, 9) -b(n, 10):
    seq(a(n), n=9..40);

Formula

E.g.f.: 1/(1-Sum_{j>=9} x^j/j!) - 1/(1-Sum_{j>=10} x^j/j!).
a(n) = A245794(n) - A245795(n) = A245732(n,9) - A245732(n,10).
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