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.

Showing 1-5 of 5 results.

A094419 Generalized ordered Bell numbers Bo(6,n).

Original entry on oeis.org

1, 6, 78, 1518, 39390, 1277646, 49729758, 2258233998, 117196187550, 6842432930766, 443879517004638, 31674687990494478, 2465744921215207710, 207943837884583262286, 18885506918597311159518, 1837699347783655374914958, 190743171535070652261555870, 21035482423625416328497024206
Offset: 0

Views

Author

Ralf Stephan, May 02 2004

Keywords

Comments

Sixth row of array A094416, which has more information.

Crossrefs

Programs

  • Magma
    A094416:= func< n,k | (&+[Factorial(j)*n^j*StirlingSecond(k,j): j in [0..k]]) >;
    A094419:= func< k | A094416(6,k) >;
    [A094419(n): n in [0..30]]; // G. C. Greubel, Jan 12 2024
    
  • Mathematica
    t = 30; Range[0, t]! CoefficientList[Series[1/(7 - 6 Exp[x]),{x, 0, t}], x] (* Vincenzo Librandi, Mar 16 2014 *)
  • PARI
    my(N=25,x='x+O('x^N)); Vec(serlaplace(1/(7-6*exp(x)))) \\ Joerg Arndt, Jan 15 2024
    
  • PARI
    a(n) = (-1)^(n+1)*polylog(-n, 7/6)/7; \\ Seiichi Manyama, Jun 01 2025
  • SageMath
    def A094416(n,k): return sum(factorial(j)*n^j*stirling_number2(k,j) for j in range(k+1)) # array
    def A094419(k): return A094416(6,k)
    [A094419(n) for n in range(31)] # G. C. Greubel, Jan 12 2024
    

Formula

E.g.f.: 1/(7 - 6*exp(x)).
a(n) = Sum_{k=0..n} A131689(n,k) * 6^k. - Philippe Deléham, Nov 03 2008
a(n) ~ n! / (7*(log(7/6))^(n+1)). - Vaclav Kotesovec, Mar 14 2014
a(0) = 1; a(n) = 6 * Sum_{k=1..n} binomial(n,k) * a(n-k). - Ilya Gutkovskiy, Jan 17 2020
a(0) = 1; a(n) = 6 * a(n-1) - 7 * Sum_{k=1..n-1} (-1)^k * binomial(n-1,k) * a(n-k). - Seiichi Manyama, Nov 17 2023
From Seiichi Manyama, Jun 01 2025: (Start)
a(n) = (-1)^(n+1)/7 * Li_{-n}(7/6), where Li_{n}(x) is the polylogarithm function.
a(n) = (1/7) * Sum_{k>=0} k^n * (6/7)^k.
a(n) = (6/7) * Sum_{k=0..n} 7^k * (-1)^(n-k) * A131689(n,k) for n > 0. (End)

A384514 Expansion of e.g.f. 6/(7 - exp(6*x)).

Original entry on oeis.org

1, 1, 8, 78, 960, 14736, 272448, 5881968, 145105920, 4026744576, 124159039488, 4211132779008, 155814875873280, 6245695887446016, 269610827961212928, 12469729905669224448, 615184657168540631040, 32246522356406129197056, 1789714914567248392224768
Offset: 0

Views

Author

Seiichi Manyama, Jun 01 2025

Keywords

Crossrefs

Programs

  • PARI
    a(n) = (-6)^(n+1)*polylog(-n, 7)/7;

Formula

a(n) = (-6)^(n+1)/7 * Li_{-n}(7), where Li_{n}(x) is the polylogarithm function.
a(n) = 6^(n+1) * Sum_{k>=0} k^n * (1/7)^(k+1).
a(n) = Sum_{k=0..n} 6^(n-k) * k! * Stirling2(n,k).
a(n) = (1/7) * Sum_{k=0..n} 7^k * (-6)^(n-k) * k! * Stirling2(n,k) for n > 0.
a(0) = 1; a(n) = Sum_{k=1..n} 6^(k-1) * binomial(n,k) * a(n-k).
a(0) = 1; a(n) = a(n-1) + 7 * Sum_{k=1..n-1} (-6)^(k-1) * binomial(n-1,k) * a(n-k).

A384521 Expansion of e.g.f. 5/(7 - 2*exp(5*x)).

Original entry on oeis.org

1, 2, 18, 218, 3474, 69290, 1659330, 46359770, 1480241970, 53171142410, 2122154748450, 93168872862650, 4462242691496850, 231524863130863850, 12936797161953970050, 774495903492069700250, 49458416187322116299250, 3355754824852804221058250, 241081466990843266748993250
Offset: 0

Views

Author

Seiichi Manyama, Jun 01 2025

Keywords

Crossrefs

Programs

  • PARI
    a(n) = (-5)^(n+1)*polylog(-n, 7/2)/7;

Formula

a(n) = (-5)^(n+1)/7 * Li_{-n}(7/2), where Li_{n}(x) is the polylogarithm function.
a(n) = 5^(n+1)/7 * Sum_{k>=0} k^n * (2/7)^k.
a(n) = Sum_{k=0..n} 2^k * 5^(n-k) * k! * Stirling2(n,k).
a(n) = (2/7) * Sum_{k=0..n} 7^k * (-5)^(n-k) * k! * Stirling2(n,k) for n > 0.
a(0) = 1; a(n) = 2 * Sum_{k=1..n} 5^(k-1) * binomial(n,k) * a(n-k).
a(0) = 1; a(n) = 2 * a(n-1) + 7 * Sum_{k=1..n-1} (-5)^(k-1) * binomial(n-1,k) * a(n-k).

A384522 Expansion of e.g.f. 4/(7 - 3*exp(4*x)).

Original entry on oeis.org

1, 3, 30, 426, 8040, 189768, 5375280, 177632976, 6708685440, 285038686848, 13456362881280, 698786099602176, 39586707755811840, 2429498408440009728, 160571526535426529280, 11370607719608891467776, 858870213271187908362240, 68928740686010010238353408
Offset: 0

Views

Author

Seiichi Manyama, Jun 01 2025

Keywords

Crossrefs

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[4/(7-3Exp[4x]),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jun 21 2025 *)
  • PARI
    a(n) = (-4)^(n+1)*polylog(-n, 7/3)/7;

Formula

a(n) = (-4)^(n+1)/7 * Li_{-n}(7/3), where Li_{n}(x) is the polylogarithm function.
a(n) = 4^(n+1)/7 * Sum_{k>=0} k^n * (3/7)^k.
a(n) = Sum_{k=0..n} 3^k * 4^(n-k) * k! * Stirling2(n,k).
a(n) = (3/7) * Sum_{k=0..n} 7^k * (-4)^(n-k) * k! * Stirling2(n,k) for n > 0.
a(0) = 1; a(n) = 3 * Sum_{k=1..n} 4^(k-1) * binomial(n,k) * a(n-k).
a(0) = 1; a(n) = 3 * a(n-1) + 7 * Sum_{k=1..n-1} (-4)^(k-1) * binomial(n-1,k) * a(n-k).

A384524 Expansion of e.g.f. 2/(7 - 5*exp(2*x)).

Original entry on oeis.org

1, 5, 60, 1070, 25440, 756080, 26964960, 1121963120, 53351831040, 2854122433280, 169649803023360, 11092432778385920, 791204615734640640, 61138238969353748480, 5087702653663698677760, 453621615686933964830720, 43141424825262182799114240, 4359374368561019960377671680
Offset: 0

Views

Author

Seiichi Manyama, Jun 01 2025

Keywords

Crossrefs

Programs

  • Maple
    A384524:=proc(n)
        add(5^k * 2^(n-k) * k! * combinat[stirling2](n,k) ,k=0..n) ;
    end proc:
    seq(A384524(n), n=0..40); # R. J. Mathar, Jun 04 2025
  • PARI
    a(n) = (-2)^(n+1)*polylog(-n, 7/5)/7;

Formula

a(n) = (-2)^(n+1)/7 * Li_{-n}(7/5), where Li_{n}(x) is the polylogarithm function.
a(n) = 2^(n+1)/7 * Sum_{k>=0} k^n * (5/7)^k.
a(n) = Sum_{k=0..n} 5^k * 2^(n-k) * k! * Stirling2(n,k).
a(n) = (5/7) * Sum_{k=0..n} 7^k * (-2)^(n-k) * k! * Stirling2(n,k) for n > 0.
a(0) = 1; a(n) = 5 * Sum_{k=1..n} 2^(k-1) * binomial(n,k) * a(n-k).
a(0) = 1; a(n) = 5 * a(n-1) + 7 * Sum_{k=1..n-1} (-2)^(k-1) * binomial(n-1,k) * a(n-k).
Showing 1-5 of 5 results.