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 11-20 of 29 results. Next

A295385 a(n) = n!*Sum_{k=0..n} binomial(2*n,n-k)*n^k/k!.

Original entry on oeis.org

1, 3, 32, 579, 14736, 483115, 19376928, 918980139, 50306339072, 3121729082739, 216541483852800, 16603614676249843, 1394473165806440448, 127308860552307549531, 12553171419275174137856, 1329537514269062031406875, 150531055969843353812533248, 18143286205523964035258551651
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 21 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(2*n,n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
  • Mathematica
    Table[n! SeriesCoefficient[Exp[n x/(1 - x)]/(1 - x)^(n + 1), {x, 0, n}], {n, 0, 17}]
    Table[n! LaguerreL[n, n, -n], {n, 0, 17}]
    Table[(-1)^n HypergeometricU[-n, n + 1, -n], {n, 0, 17}]
    Join[{1}, Table[n! Sum[Binomial[2 n, n - k] n^k/k!, {k, 0, n}], {n, 1, 17}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0,n, binomial(2*n,n-k)*n^k/k!), ", ")) \\ G. C. Greubel, Feb 06 2018
    

Formula

a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(n+1).
a(n) = n!*Laguerre(n,n,-n).
a(n) ~ 2^(n - 1/2) * (1 + sqrt(2))^(n + 1/2) * n^n / exp((2 - sqrt(2))*n). - Vaclav Kotesovec, Nov 21 2017

A295406 a(n) = n! * Laguerre(n, 2*n, -n).

Original entry on oeis.org

1, 4, 58, 1422, 49000, 2174360, 118023264, 7574532826, 561071549056, 47111034709260, 4421715905632000, 458741213603157254, 52129735913348001792, 6439324687323193520608, 859089518697047400878080, 123108032319553206480143250, 18858657171509448248927617024
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 22 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(3*n,n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
  • Mathematica
    Table[n!*LaguerreL[n,2*n,-n],{n,0,15}]
    Join[{1},Table[n!*Sum[Binomial[3*n, n-k]*n^k/k!, {k, 0, n}], {n, 1, 15}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0, n, binomial(3*n,n-k)*n^k/k!), ", ")) \\ G. C. Greubel, Feb 06 2018
    
  • PARI
    a(n) = n!*pollaguerre(n, 2*n, -n); \\ Michel Marcus, Feb 05 2021
    

Formula

a(n) = n!*Sum_{k=0..n} binomial(3*n,n-k)*n^k/k!.
a(n) ~ sqrt(1/2 + 5/(2*sqrt(13))) * ((11 + sqrt(13))/2)^n * exp((sqrt(13)-5)*n/2) * n^n.
a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(2*n+1). - Ilya Gutkovskiy, Nov 23 2017

A295407 a(n) = n! * Laguerre(n, 3*n, -n).

Original entry on oeis.org

1, 5, 92, 2859, 124832, 7018105, 482598720, 39236322839, 3681751480832, 391611920476653, 46560370087846400, 6119025385880816035, 880818377346674454528, 137824220501484017301281, 23291983597732334528110592, 4228010378355969165140319375
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 22 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(4*n,n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
  • Mathematica
    Table[n!*LaguerreL[n,3*n,-n],{n,0,15}]
    Join[{1},Table[n!*Sum[Binomial[4*n, n-k]*n^k/k!, {k, 0, n}], {n, 1, 15}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0, n, binomial(4*n,n-k)*n^k/k!), ", ")) \\ G. C. Greubel, Feb 06 2018
    
  • PARI
    a(n) = n!*pollaguerre(n, 3*n, -n); \\ Michel Marcus, Feb 05 2021
    

Formula

a(n) = n!*Sum_{k=0..n} binomial(4*n,n-k)*n^k/k!.
a(n) ~ sqrt(1/2 + 3/(2*sqrt(5))) * (8*(sqrt(5)-1))^n * exp((sqrt(5)-3)*n) * n^n.
a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(3*n+1). - Ilya Gutkovskiy, Nov 23 2017

A295408 a(n) = n! * Laguerre(n, 4*n, -n).

Original entry on oeis.org

1, 6, 134, 5052, 267576, 18246850, 1521907056, 150077897088, 17080661438336, 2203559337858174, 317761804144896000, 50650336389453807556, 8843008543955452118016, 1678231571506037926192698, 343989152383931539269349376, 75733086648535784012234565000
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 22 2017

Keywords

Comments

In general, for fixed m >= 1, n! * Sum_{k=0..n} binomial(m*n, n-k) * n^k / k! = n! * Laguerre(n, (m-1)*n, -n) ~ sqrt(1/2 + (m + 2)/(2*sqrt(m^2 + 4))) * (2^(m+1) * m^m / ((sqrt(m^2 + 4) - m) * (m - 2 + sqrt(m^2 + 4))^m))^n * exp((sqrt(m^2 + 4) - m)*n/2 - n) * n^n.

Crossrefs

Cf. A277373 (m=1), A295385 (m=2), A295406 (m=3), A295407 (m=4).

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(5*n,n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
  • Mathematica
    Table[n!*LaguerreL[n,4*n,-n],{n,0,15}]
    Join[{1},Table[n!*Sum[Binomial[5*n,n-k]*n^k/k!,{k,0,n}],{n,1,15}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0, n, binomial(5*n,n-k)*n^k/k!), ", ")) \\ G. C. Greubel, Feb 06 2018
    
  • PARI
    a(n) = n!*pollaguerre(n, 4*n, -n); \\ Michel Marcus, Feb 05 2021
    

Formula

a(n) = n!*Sum_{k=0..n} binomial(5*n,n-k)*n^k/k!.
a(n) ~ sqrt(1/2 + 7/(2*sqrt(29))) * (131 - 22*sqrt(29))^n * exp((sqrt(29)-7)*n/2) * n^n.
a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(4*n+1). - Ilya Gutkovskiy, Nov 23 2017

A295409 a(n) = n! * Laguerre(n, n^2, -n).

Original entry on oeis.org

1, 3, 58, 2859, 267576, 40818095, 9235507968, 2906955312471, 1215257338052992, 651548571287972859, 435901423022852332800, 356000439852418418920643, 348583395952381998326141952, 403108990190536860168604229031, 543577365164816368801494214352896
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 22 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(n*(n+1), n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, May 11 2018
  • Maple
    seq(n!*orthopoly[L](n,n^2,-n),n=0..30); # Robert Israel, Nov 22 2017
  • Mathematica
    Table[n!*LaguerreL[n,n^2,-n],{n,0,15}]
    Join[{1},Table[n!*Sum[Binomial[n*(n+1),n-k]*n^k/k!,{k,0,n}],{n,1,15}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0,30, binomial(n*(n+1), n-k)*n^k/k!), ", ")) \\ G. C. Greubel, May 11 2018
    
  • PARI
    a(n) = n!*pollaguerre(n, n^2, -n); \\ Michel Marcus, Feb 05 2021
    

Formula

a(n) = n! * Sum_{k=0..n} binomial(n*(n+1),n-k)*n^k/k!.
a(n) ~ exp(3/2) * n^(2*n).
a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(n^2+1). - Ilya Gutkovskiy, Nov 23 2017

A330260 a(n) = n! * Sum_{k=0..n} binomial(n,k) * n^(n - k) / k!.

Original entry on oeis.org

1, 2, 17, 352, 13505, 830126, 74717857, 9263893892, 1513712421377, 315230799073690, 81499084718806001, 25612081645835777192, 9615370149488574778177, 4250194195208050117007942, 2184834047906975645398282625, 1292386053018890618812398220876
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 18 2019

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*&+[Binomial(n,k)*n^(n-k)/Factorial(k):k in [0..n]]:n in [0..15]]; // Marius A. Burtea, Dec 18 2019
  • Mathematica
    Join[{1}, Table[n! Sum[Binomial[n, k] n^(n - k)/k!, {k, 0, n}], {n, 1, 15}]]
    Join[{1}, Table[n^n n! LaguerreL[n, -1/n], {n, 1, 15}]]
    Table[n! SeriesCoefficient[Exp[x/(1 - n x)]/(1 - n x), {x, 0, n}], {n, 0, 15}]
  • PARI
    a(n) = n! * sum(k=0, n, binomial(n,k) * n^(n-k)/k!); \\ Michel Marcus, Dec 18 2019
    

Formula

a(n) = n! * [x^n] exp(x/(1 - n*x)) / (1 - n*x).
a(n) = Sum_{k=0..n} binomial(n,k)^2 * n^k * k!.
a(n) ~ sqrt(2*Pi) * BesselI(0,2) * n^(2*n + 1/2) / exp(n). - Vaclav Kotesovec, Dec 18 2019

A295418 a(n) = n! * Laguerre(n, n*(n-1), -n).

Original entry on oeis.org

1, 2, 32, 1422, 124832, 18246850, 4005713952, 1232956594814, 506672220394496, 267992015325604578, 177340024595660672000, 143531889358151618790862, 139482579412432078779322368, 160267575964062522718064075618, 214924620455826226723051817295872
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 22 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[Binomial(n^2, n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..25]]; // G. C. Greubel, May 13 2018
  • Mathematica
    Table[n!*LaguerreL[n,n*(n-1),-n],{n,0,15}]
    Join[{1},Table[n!*Sum[Binomial[n^2,n-k]*n^k/k!,{k,0,n}],{n,1,15}]]
  • PARI
    for(n=0,25, print1(n!*sum(k=0,n, binomial(n^2, n-k)*n^k/k!), ", ")) \\ G. C. Greubel, May 13 2018
    
  • PARI
    a(n) = n!*pollaguerre(n, n*(n-1), -n); \\ Michel Marcus, Feb 05 2021
    

Formula

a(n) = n! * Sum_{k=0..n} binomial(n^2,n-k)*n^k/k!.
a(n) ~ exp(1/2) * n^(2*n).
a(n) = n! * [x^n] exp(n*x/(1 - x))/(1 - x)^(n^2-n+1). - Ilya Gutkovskiy, Nov 23 2017

A343849 a(n) = Sum_{k = 0..n} n! * LaguerreL(n, -k).

Original entry on oeis.org

1, 3, 23, 294, 5194, 116620, 3175717, 101696700, 3745365444, 155975005998, 7247927859875, 371803988506742, 20870023274690966, 1272424816703533792, 83736949788656865729, 5916106654032037435800, 446636583718649775483144, 35882981062654529341219962, 3056767877633271802374850239
Offset: 0

Views

Author

Peter Luschny, May 08 2021

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := Sum[n! LaguerreL[n, -k], {k, 0, n}];
    Table[a[n], {n, 0, 18}]
  • PARI
    a(n) = n!*sum(m=0, n, sum(j=0, n, binomial(n, j) * m^j / j!))
    for(n=0, 18, print(a(n)))

Formula

a(n) = (-1)^n * Sum_{k=0..n} KummerU(-n, 1, -k).
a(n) = n! * Sum_{m=0..n} Sum_{j=0..n} binomial(n, j) * m^j / j!.
a(n) ~ exp(n/phi - n) * phi^(2*n+1) * n^n / (5^(1/4) * (1 - exp(-1/phi))), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio. - Vaclav Kotesovec, May 09 2021

A344048 T(n, k) = n! * [x^n] exp(k * x/(1 - x))/(1 - x). Triangle read by rows, T(n, k) for 0 <= k <= n.

Original entry on oeis.org

1, 1, 2, 2, 7, 14, 6, 34, 86, 168, 24, 209, 648, 1473, 2840, 120, 1546, 5752, 14988, 32344, 61870, 720, 13327, 58576, 173007, 414160, 866695, 1649232, 5040, 130922, 671568, 2228544, 5876336, 13373190, 27422352, 51988748
Offset: 0

Views

Author

Peter Luschny, May 08 2021

Keywords

Examples

			Triangle starts:
[0]    1;
[1]    1,      2;
[2]    2,      7,     14;
[3]    6,     34,     86,     168;
[4]   24,    209,    648,    1473,    2840;
[5]  120,   1546,   5752,   14988,   32344,    61870;
[6]  720,  13327,  58576,  173007,  414160,   866695,  1649232;
[7] 5040, 130922, 671568, 2228544, 5876336, 13373190, 27422352, 51988748;
.
Array whose upward read antidiagonals are the rows of the triangle.
n\k   0       1        2          3           4              5
--------------------------------------------------------------------
[0]   1,      2,      14,       168,        2840,         61870, ...
[1]   1,      7,      86,      1473,       32344,        866695, ...
[2]   2,     34,     648,     14988,      414160,      13373190, ...
[3]   6,    209,    5752,    173007,     5876336,     224995745, ...
[4]  24,   1546,   58576,   2228544,    91356544,    4094022230, ...
[5] 120,  13327,  671568,  31636449,  1542401920,   80031878175, ...
[6] 720, 130922, 8546432, 490102164, 28075364096, 1671426609550, ...
		

Crossrefs

T(n, n) = A277373(n). T(2*n, n) = A344049(n). Row sums are A343849.
Cf. A343847.

Programs

  • Maple
    # Rows of the array:
    A := (n, k) -> (n + k)!*LaguerreL(n + k, -k):
    seq(print(seq(simplify(A(n, k)), k = 0..6)), n = 0..6);
    # Columns of the array:
    egf := n -> exp(n*x/(1-x))/(1-x): ser := n -> series(egf(n), x, 16):
    C := (k, n) -> (n + k)!*coeff(ser(k), x, n + k):
    seq(print(seq(C(k, n), n = 0..6)), k=0..6);
  • Mathematica
    T[n_, k_] := (-1)^(n) HypergeometricU[-n, 1,  -k];
    Table[T[n, k], {n, 0, 7}, {k, 0, n}]  // Flatten
    (* Alternative: *)
    T[n_, k_] := n ! LaguerreL[n , -k];
    Table[T[n, k], {n, 0, 7}, {k, 0, n}] // Flatten
  • PARI
    T(n, k) = n! * sum(j=0, n, binomial(n, j) * k^j / j!)
    for(n=0, 9, for(k=0, n, print(T(n, k))))
  • SageMath
    # Columns of the array:
    def column(k, len):
        R. = PowerSeriesRing(QQ, default_prec=len+k)
        f = exp(k * x / (1 - x)) / (1 - x)
        return f.egf_to_ogf().list()[k:]
    for col in (0..6): print(column(col, 8))
    # Alternative:
    @cached_function
    def L(n, x):
        if n == 0: return 1
        if n == 1: return 1 - x
        return (L(n-1, x) * (2*n - 1 - x) - L(n-2, x)*(n - 1)) / n
    A344048 = lambda n, k: factorial(n)*L(n, -k)
    print(flatten([[A344048(n, k) for k in (0..n)] for n in (0..7)]))
    

Formula

T(n, k) = (-1)^n*U(-n, 1, -k), where U is the Kummer U function.
T(n, k) = n! * L(n, -k), where L is the Laguerre polynomial function.
T(n, k) = n! * Sum_{j=0..n} binomial(n, j) * k^j / j!.

A295384 a(n) = n!*Sum_{k=0..n} (-1)^k*binomial(2*n,n-k)*n^k/k!.

Original entry on oeis.org

1, 1, 0, -15, -112, -135, 9504, 152425, 610560, -27692847, -765107200, -6289891839, 213472972800, 9380264146825, 129378550468608, -3294028613874375, -226623617585053696, -4707649131227927775, 83803818828756418560, 9446689798312021406353, 277055229100887244800000
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 21 2017

Keywords

Crossrefs

Programs

  • Magma
    [Factorial(n)*(&+[(-1)^k*Binomial(2*n,n-k)*n^k/Factorial(k): k in [0..n]]): n in [0..30]]; // G. C. Greubel, Feb 06 2018
  • Maple
    a := n -> pochhammer(n, n)*hypergeom([1 - n], [n], n):
    seq(simplify(a(n)), n = 0..20); # Peter Luschny, Mar 23 2023
  • Mathematica
    Table[n! SeriesCoefficient[Exp[-n x/(1 - x)]/(1 - x)^(n + 1), {x, 0, n}], {n, 0, 20}]
    Table[n! LaguerreL[n, n, n], {n, 0, 20}]
    Table[(-1)^n HypergeometricU[-n, n + 1, n], {n, 0, 20}]
    Join[{1}, Table[n! Sum[(-1)^k Binomial[2 n, n - k] n^k/k!, {k, 0, n}], {n, 1, 20}]]
  • PARI
    for(n=0,30, print1(n!*sum(k=0,n, (-1)^k*binomial(2*n,n-k)*n^k/k!), ", ")) \\ G. C. Greubel, Feb 06 2018
    

Formula

a(n) = n! * [x^n] exp(-n*x/(1 - x))/(1 - x)^(n+1).
a(n) = n!*Laguerre(n,n,n).
a(n) = Pochhammer(n, n)*hypergeom([1 - n], [n], n). - Peter Luschny, Mar 23 2023
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