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.

A291132 Number of defective parking functions of length n and defect six.

Original entry on oeis.org

1, 303, 34660, 2743112, 181875244, 11023248678, 639875755364, 36555471741284, 2090131479753756, 120898503338385149, 7124218746544184628, 429662666436736162636, 26601747798152634836236, 1694092238645618305809580, 111106187207006959809867012
Offset: 7

Views

Author

Alois P. Heinz, Aug 18 2017

Keywords

Crossrefs

Column k=6 of A264902.

Programs

  • Maple
    S:= (n, k)-> add(binomial(n, i)*k*(k+i)^(i-1)*(n-k-i)^(n-i), i=0..n-k):
    a:= n-> S(n, 6)-S(n, 7):
    seq(a(n), n=7..23);
  • Mathematica
    S[n_, k_] := Sum[Binomial[n, i]*k*(k+i)^(i-1)*(n-k-i)^(n-i), {i, 0, n-k}];
    a[n_] := S[n, 6] - S[n, 7];
    Table[a[n], {n, 7, 23}] (* Jean-François Alcover, Feb 24 2019, from Maple *)

Formula

a(n) ~ (43*exp(1)/720 - 88*exp(2)/15 + 405*exp(3)/8 - 368*exp(4)/3 + 235*exp(5)/2 - 48*exp(6) + 7*exp(7)) * n^(n-1). - Vaclav Kotesovec, Aug 19 2017

A291133 Number of defective parking functions of length n and defect seven.

Original entry on oeis.org

1, 574, 96620, 10358998, 886044810, 66943181150, 4719570364004, 320771944968342, 21454694483447459, 1431385710008667470, 96133394595460111056, 6540549310477955461846, 452777288307033641080180, 31990399760398854681388158, 2311790354938282481939931160
Offset: 8

Views

Author

Alois P. Heinz, Aug 18 2017

Keywords

Crossrefs

Column k=7 of A264902.

Programs

  • Maple
    S:= (n, k)-> add(binomial(n, i)*k*(k+i)^(i-1)*(n-k-i)^(n-i), i=0..n-k):
    a:= n-> S(n, 7)-S(n, 8):
    seq(a(n), n=8..23);
  • Mathematica
    S[n_, k_] := Sum[Binomial[n, i]*k*(k+i)^(i-1)*(n-k-i)^(n-i), {i, 0, n-k}];
    a[n_] := S[n, 7] - S[n, 8];
    Table[a[n], {n, 8, 23}] (* Jean-François Alcover, Feb 24 2019, from Maple *)

Formula

a(n) ~ (-19*exp(1)/1680 + 116*exp(2)/45 - 1593*exp(3)/40 + 160*exp(4) - 1525*exp(5)/6 + 186*exp(6) - 63*exp(7) + 8*exp(8)) * n^(n-1). - Vaclav Kotesovec, Aug 19 2017

A291134 Number of defective parking functions of length n and defect eight.

Original entry on oeis.org

1, 1103, 269512, 38643849, 4218834608, 393933602129, 33499946915016, 2693983725947891, 209859823775671984, 16093162912317174422, 1228462028909579534968, 94081283153407041089350, 7269699339591280955315232, 569088494101518607733459806
Offset: 9

Views

Author

Alois P. Heinz, Aug 18 2017

Keywords

Crossrefs

Column k=8 of A264902.

Programs

  • Maple
    S:= (n, k)-> add(binomial(n, i)*k*(k+i)^(i-1)*(n-k-i)^(n-i), i=0..n-k):
    a:= n-> S(n, 8)-S(n, 9):
    seq(a(n), n=9..23);
  • Mathematica
    S[n_, k_] := Sum[Binomial[n, i]*k*(k+i)^(i-1)*(n-k-i)^(n-i), {i, 0, n-k}];
    a[n_] := S[n, 8] - S[n, 9];
    Table[a[n], {n, 9, 23}] (* Jean-François Alcover, Feb 24 2019, from Maple *)

Formula

a(n) ~ (73*exp(1)/40320 - 296*exp(2)/315 + 405*exp(3)/16 - 2432*exp(4)/15 + 9625*exp(5)/24 - 468*exp(6) + 553*exp(7)/2 - 80*exp(8) + 9*exp(9)) * n^(n-1). - Vaclav Kotesovec, Aug 19 2017

A291135 Number of defective parking functions of length n and defect nine.

Original entry on oeis.org

1, 2146, 754943, 143336610, 19795924787, 2267392009178, 231141766226605, 21881366451890002, 1976997422623843358, 173666031731576614842, 15025473411620865716938, 1292364106829281911023554, 111260031164008673095102874, 9635674549219284395173044506
Offset: 10

Views

Author

Alois P. Heinz, Aug 18 2017

Keywords

Crossrefs

Column k=9 of A264902.

Programs

  • Maple
    S:= (n, k)-> add(binomial(n, i)*k*(k+i)^(i-1)*(n-k-i)^(n-i), i=0..n-k):
    a:= n-> S(n, 9)-S(n, 10):
    seq(a(n), n=10..23);
  • Mathematica
    S[n_, k_] := Sum[Binomial[n, i]*k*(k+i)^(i-1)*(n-k-i)^(n-i), {i, 0, n-k}];
    a[n_] := S[n, 9] - S[n, 10];
    Table[a[n], {n, 10, 23}] (* Jean-François Alcover, Feb 24 2019, from Maple *)

Formula

a(n) ~ (-13*exp(1)/51840 + 92*exp(2)/315 - 7533*exp(3)/560 + 6016*exp(4)/45 - 11875*exp(5)/24 + 864*exp(6) - 4753*exp(7)/6 + 392*exp(8) - 99*exp(9) + 10*exp(10)) * n^(n-1). - Vaclav Kotesovec, Aug 19 2017

A291136 Number of defective parking functions of length n and defect ten.

Original entry on oeis.org

1, 4215, 2127828, 530926606, 92071525556, 12851428617547, 1561750852160556, 173226805226723844, 18081637592017744356, 1813499364725872444178, 177350996523515552397628, 17092810524840161845093436, 1636375630004710170560408532, 156537967540558397590739941650
Offset: 11

Views

Author

Alois P. Heinz, Aug 18 2017

Keywords

Crossrefs

Column k=10 of A264902.

Programs

  • Maple
    S:= (n, k)-> add(binomial(n, i)*k*(k+i)^(i-1)*(n-k-i)^(n-i), i=0..n-k):
    a:= n-> S(n, 10)-S(n, 11):
    seq(a(n), n=11..23);
  • Mathematica
    S[n_, k_] := Sum[Binomial[n, i]*k*(k+i)^(i-1)*(n-k-i)^(n-i), {i, 0, n-k}];
    a[n_] := S[n, 10] - S[n, 11];
    Table[a[n], {n, 11, 23}] (* Jean-François Alcover, Feb 24 2019, from Maple *)

Formula

a(n) ~ (37*exp(1)/1209600 - 32*exp(2)/405 + 27459*exp(3)/4480 - 9728*exp(4)/105 + 71875*exp(5)/144 - 6264*exp(6)/5 + 13377*exp(7)/8 - 3776*exp(8)/3 + 1071*exp(9)/2 - 120*exp(10) + 11*exp(11)) * n^(n-1). - Vaclav Kotesovec, Aug 19 2017

A365623 T(n,k) is the number of parking functions of length n with cars parking at most k spots away from their preferred spot; square array T(n,k), n>=0, k>=0, read by downward antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 3, 6, 1, 1, 3, 13, 24, 1, 1, 3, 16, 75, 120, 1, 1, 3, 16, 109, 541, 720, 1, 1, 3, 16, 125, 918, 4683, 5040, 1, 1, 3, 16, 125, 1171, 9277, 47293, 40320, 1, 1, 3, 16, 125, 1296, 12965, 109438, 545835, 362880, 1, 1, 3, 16, 125, 1296, 15511, 166836, 1475691, 7087261, 3628800
Offset: 0

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Author

Keywords

Examples

			Square array T(n,k) begins:
    1,    1,    1,     1,     1,     1,     1, ...
    1,    1,    1,     1,     1,     1,     1, ...
    2,    3,    3,     3,     3,     3,     3, ...
    6,   13,   16,    16,    16,    16,    16, ...
   24,   75,  109,   125,   125,   125,   125, ...
  120,  541,  918,  1171,  1296,  1296,  1296, ...
  720, 4683, 9277, 12965, 15511, 16807, 16807, ...
  ...
		

Crossrefs

Columns k=0..1, 3..4 give: A000142, A000670, A365626, A365627.
Main diagonal gives A000272(n+1).
Cf. A264902.

Programs

  • Maple
    T:= proc(n, k) option remember; `if`(n=0, 1, add(min(i+1, k+1)*
           binomial(n-1, i)*T(i, k)*T(n-1-i, k), i=0..n-1))
        end:
    seq(seq(T(n, d-n), n=0..d), d=0..10);  # Alois P. Heinz, Sep 13 2023

Formula

T(n,k) = Sum_{i=0..n-1} binomial(n-1,i) * min(i+1,k+1) * T(i,k) * T(n-1-i,k) for n>0, T(0,k) = 1.
Previous Showing 11-16 of 16 results.