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.

A094869 E.g.f.: exp(5x)/(1-5x)^(1/5).

Original entry on oeis.org

1, 6, 41, 356, 4401, 78826, 1893481, 56341416, 1978638881, 79749105326, 3622010623401, 182895318578956, 10160561511881041, 615728464210461906, 40414538467581457001, 2855999961062529064976, 216180544920721807887681
Offset: 0

Views

Author

Philippe Deléham, Jun 16 2004

Keywords

Comments

Sum_{k = 0..n} A046716(n,k)*x^k give A000522(n), A081367(n), A094822(n), A094856(n) for x = 1, 2, 3, 4 respectively.

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[Exp[5x]/(1-5x)^(1/5),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, May 19 2014 *)

Formula

a(n) = Sum_{k = 0..n} A046716(n, k)*5^k.
Conjectured to be D-finite with recurrence: a(n) +(-5*n-1)*a(n-1) +25*(n-1)*a(n-2)=0. - R. J. Mathar, Nov 15 2019
a(n) ~ sqrt(2*Pi) * 5^n * n^(n - 3/10) / (Gamma(1/5) * exp(n-1)). - Vaclav Kotesovec, Nov 19 2021

A094905 Expansion of e.g.f.: exp(6*x)/(1-6*x)^(1/6).

Original entry on oeis.org

1, 7, 55, 541, 7585, 157231, 4452247, 157484725, 6594785281, 317357589655, 17222102537911, 1039632137764237, 69073193451776545, 5007661199176196671, 393324947394545293975, 33268708968518818629541
Offset: 0

Views

Author

Philippe Deléham, Jun 16 2004

Keywords

Comments

Sum_{k = 0..n} A046716(n,k)*x^k give A000522(n), A081367(n), A094822(n), A094856(n), A094869(n) for x = 1, 2, 3, 4, 5 respectively.

Crossrefs

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[Exp[6x]/Surd[1-6x,6],{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Dec 15 2022 *)

Formula

E.g.f.: exp(6*x)/(1-6*x)^(1/6).
a(n) = Sum_{k = 0..n} A046716(n, k)*6^k.
Conjectured to be D-finite with recurrence: a(n) +(-6*n-1)*a(n-1) +36*(n-1)*a(n-2) = 0. - R. J. Mathar, Nov 15 2019
a(n) ~ sqrt(Pi) * 2^(n + 1/2) * 3^n * n^(n - 1/3) / (Gamma(1/6) * exp(n - 1)). - Vaclav Kotesovec, Nov 19 2021

A059098 Triangle read by rows. T(n, k) = Sum_{i=0..n} Stirling2(n, i)*Product_{j=1..k} (i - j + 1) for 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 2, 3, 2, 5, 10, 12, 6, 15, 37, 62, 60, 24, 52, 151, 320, 450, 360, 120, 203, 674, 1712, 3120, 3720, 2520, 720, 877, 3263, 9604, 21336, 33600, 34440, 20160, 5040, 4140, 17007, 56674, 147756, 287784, 394800, 352800, 181440, 40320, 21147, 94828
Offset: 0

Views

Author

Vladeta Jovovic, Jan 02 2001

Keywords

Comments

The transpose of this lower unitriangular array is the U factor in the LU decomposition of the Hankel matrix (Bell(i+j-2))A000110(n).%20The%20L%20factor%20is%20A049020%20(see%20Chamberland,%20p.%201672).%20-%20_Peter%20Bala">i,j >= 1, where Bell(n) = A000110(n). The L factor is A049020 (see Chamberland, p. 1672). - _Peter Bala, Oct 15 2023

Examples

			Triangle begins:
  [0] [ 1]
  [1] [ 1,    1]
  [2] [ 2,    3,    2]
  [3] [ 5,   10,   12,    6]
  [4] [15,   37,   62,   60,   24]
  [5] [52,  151,  320,  450,  360,  120]
  [6] [203, 674, 1712, 3120, 3720, 2520, 720]
  ...;
E.g.f. for T(n, 2) = (exp(x)-1)^2*(exp(exp(x)-1)) = x^2 + 2*x^3 + 31/12*x^4 + 8/3*x^5 + 107/45*x^6 + 343/180*x^7 + 28337/20160*x^8 + 349/360*x^9 + ...;
E.g.f. for T(n, 3) = (exp(x)-1)^3*(exp(exp(x)-1)) = x^3 + 5/2*x^4 + 15/4*x^5 + 13/3*x^6 + 127/30*x^7 + 1759/480*x^8 + 34961/12096*x^9 + ...
		

Crossrefs

Cf. A000110(n) = T(n,0), A005493(n) = T(n,1), A059099 (row sums).

Programs

  • Maple
    T := proc(n, k) option remember; `if`(k < 0 or k > n, 0,
          `if`(n = 0, 1, k*T(n-1, k-1) + (k+1)*T(n-1, k) + T(n-1, k+1)))
        end:
    seq(print(seq(T(n, k), k = 0..n)), n = 0..15); # Peter Bala, Oct 15 2023

Formula

E.g.f. for T(n, k): (exp(x)-1)^k*(exp(exp(x)-1)).
n-th row is M^n*[1,0,0,0,...], where M is a tridiagonal matrix with all 1's in the superdiagonal, (1,2,3,...) in the main and subdiagonals; and the rest zeros. - Gary W. Adamson, Jun 23 2011
T(n, k) = k!*A049020(n, k). - R. J. Mathar, May 17 2016
T(n, k) = Sum_{j=0..k} (-1)^(k-j)*A046716(k, k-j)*Bell(n + j). - Peter Luschny, Dec 06 2023

A094911 Expansion of e.g.f. exp(7*x)/(1-7*x)^(1/7).

Original entry on oeis.org

1, 8, 71, 778, 12125, 284012, 9241891, 378595022, 18409947641, 1029827400400, 64998958518719, 4565303338264082, 353016345110857429, 29793105387299603252, 2724646021507044539675, 268374407984059193374678
Offset: 0

Views

Author

Philippe Deléham, Jun 17 2004

Keywords

Comments

Sum_{k = 0..n} A046716(n,k)*x^k give A000522(n), A081367(n), A094822(n), A094856(n), A094869(n), A094905(n) for x = 1, 2, 3, 4, 5, 6 respectively.

Crossrefs

Programs

  • PARI
    my(x='x+O('x^20)); Vec(serlaplace(exp(7*x)/(1-7*x)^(1/7))) \\ Michel Marcus, Jan 23 2023

Formula

a(n) = Sum_{k = 0..n} A046716(n, k)*7^k.
Conjectured to be D-finite with recurrence: a(n) +(-7*n-1)*a(n-1) +49*(n-1)*a(n-2)=0. - R. J. Mathar, Nov 15 2019
a(n) ~ sqrt(2*Pi) * n^(n + 1/2) * 7^n / (Gamma(1/7) * exp(n-1) * n^(6/7)). - Vaclav Kotesovec, Nov 19 2021

Extensions

Corrected by D. S. McNeil, Aug 20 2010

A094935 E.g.f.: exp(8x)/(1-8x)^(1/8).

Original entry on oeis.org

1, 9, 89, 1073, 18321, 476473, 17484457, 813648417, 45054110369, 2872362067433, 206710159889529, 16558892507010961, 1460688620617834801, 140655075719488236057, 14678730623948132120009
Offset: 0

Views

Author

Philippe Deléham, Jun 18 2004

Keywords

Comments

Sum_{k = 0..n} A046716(n,k)*x^k give A000522(n), A081367(n), A094822(n), A094856(n), A094869(n), A094905(n), A094911(n) for x = 1, 2, 3, 4, 5, 6, 7 respectively.

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[Exp[8x]/Surd[1-8x,8],{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Jan 25 2019 *)

Formula

a(n) = Sum_{k = 0..n} A046716(n, k)*8^k.
D-finite with recurrence: a(n) +(-8*n-1)*a(n-1) +64*(n-1)*a(n-2)=0. - R. J. Mathar, Nov 15 2019
a(n) ~ sqrt(2*Pi) * n^(n + 1/2) * 8^n / (Gamma(1/8) * exp(n-1) * n^(7/8)). - Vaclav Kotesovec, Nov 19 2021

A095176 E.g.f.: exp(9x)/(1-9x)^(1/9).

Original entry on oeis.org

1, 10, 109, 1432, 26497, 754894, 30787885, 1603546156, 99602138593, 7128277455538, 576063289419661, 51832424202980320, 5136461847251936929, 555721381650431686582, 65167921144448534609677
Offset: 0

Views

Author

Philippe Deléham, Jun 20 2004

Keywords

Comments

Sum_{k = 0..n} A046716(n,k)*x^k give A000522(n), A081367(n), A094822(n), A094856(n), A094869(n), A094905(n), A094911(n), A094935(n) for x = 1, 2, 3, 4, 5, 6, 7, 8 respectively.
From Vaclav Kotesovec, Nov 19 2021: (Start)
In general, for k > 0, if e.g.f. = exp(k*x) / (1 - k*x)^(1/k), then a(n) ~ sqrt(2*Pi) * n^(n + 1/2) * k^n / (Gamma(1/k) * exp(n-1) * n^(1 - 1/k)).
Equivalently, a(n) ~ n! * exp(1) * k^n / (Gamma(1/k) * n^(1 - 1/k)). (End)

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[Exp[9x]/Surd[1-9x,9],{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jul 25 2020 *)

Formula

a(n) = Sum_{k = 0..n} A046716(n, k)*9^k.
D-finite with recurrence a(n) +(-9*n-1)*a(n-1) +81*(n-1)*a(n-2)=0. - R. J. Mathar, Aug 20 2021
a(n) ~ sqrt(2*Pi) * n^(n + 1/2) * 9^n / (Gamma(1/9) * exp(n-1) * n^(8/9)). - Vaclav Kotesovec, Nov 19 2021
Previous Showing 11-16 of 16 results.