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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A322623 E.g.f.: (1 + sinh(x)) / (1 - sinh(x)).

Original entry on oeis.org

1, 2, 4, 14, 64, 362, 2464, 19574, 177664, 1814162, 20583424, 256891934, 3497611264, 51588733562, 819450793984, 13946142745094, 253171058212864, 4883182404118562, 99727612182790144, 2149854113300939054, 48784173816258494464, 1162353473295706049162, 29013549746780744187904, 757126891483681641073814, 20616734677807356197208064, 584789894473832421848925362
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2018

Keywords

Comments

Equals the antidiagonal sums of square table A322620.
a(n) = 2*A006154(n) for n >= 1.

Examples

			E.g.f.: A(x) = 1 + 2*x + 4*x^2/2! + 14*x^3/3! + 64*x^4/4! + 362*x^5/5! + 2464*x^6/6! + 19574*x^7/7! + 177664*x^8/8! + 1814162*x^9/9! + ...
where
A(x) = 1 + 2*sinh(x) + 2*sinh(x)^2 + 2*sinh(x)^3 + 2*sinh(x)^4 + ...
		

Crossrefs

Programs

  • Maple
    S:= series((1+sinh(x))/(1-sinh(x)),x,51):
    seq(coeff(S,x,j)*j!,j=0..50);  #  Robert Israel, Dec 31 2018
  • PARI
    {a(n) = my(X = x +x*O(x^n)); n! * polcoeff( (1 + sinh(X)) / (1 - sinh(X)),n)}
    for(n=0,30, print1(a(n),", "))

Formula

a(n) = Sum_{k=0..n} A322620(n-k,k), for n >= 0.
a(n) ~ sqrt(2)*n!/log(1+sqrt(2))^(n+1). - Robert Israel, Dec 31 2018

A330046 Expansion of e.g.f. exp(x) / (1 - sinh(x)).

Original entry on oeis.org

1, 2, 5, 17, 77, 437, 2975, 23627, 214457, 2189897, 24846395, 310095887, 4221990437, 62273111357, 989164604615, 16834483468547, 305604501324017, 5894522593612817, 120381876933435635, 2595103478745235607, 58887707028270711197, 1403084759749993342277
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 28 2019

Keywords

Comments

Binomial transform of A006154.

Crossrefs

Programs

  • Mathematica
    nmax = 21; CoefficientList[Series[Exp[x]/(1 - Sinh[x]), {x, 0, nmax}], x] Range[0, nmax]!

Formula

a(n) = Sum_{k=0..n} binomial(n,k) * A006154(k).
a(n) ~ n! * (1 + 1/sqrt(2)) / (log(1 + sqrt(2)))^(n+1). - Vaclav Kotesovec, Dec 03 2019

A332258 E.g.f.: 1 / (1 + x - sinh(x)).

Original entry on oeis.org

1, 0, 0, 1, 0, 1, 20, 1, 112, 1681, 492, 27721, 371624, 319177, 13461604, 171387217, 319071456, 11466038689, 143550642140, 484491620089, 15758152572952, 199089883272217, 1077471975974484, 32827750137627457, 427744154995090256, 3385134777669637681
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 08 2020

Keywords

Comments

Number of labeled ordered partitions of an n-set into odd parts > 1.

Crossrefs

Programs

  • Mathematica
    nmax = 25; CoefficientList[Series[1/(1 + x - Sinh[x]), {x, 0, nmax}], x] Range[0, nmax]!
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, 2 k - 1] a[n - 2 k + 1], {k, 2, Ceiling[n/2]}]; Table[a[n], {n, 0, 25}]
  • PARI
    seq(n)={Vec(serlaplace(1 / (1 + x - sinh(x + O(x*x^n)))))} \\ Andrew Howroyd, Feb 08 2020

Formula

a(0) = 1; a(n) = Sum_{k=2..ceiling(n/2)} binomial(n,2*k-1) * a(n-2*k+1).
a(n) ~ n! / ((cosh(r) - 1) * r^(n+1)), where r = 1.72911689821437486498840709347... is the root of the equation 1 + r - sinh(r) = 0. - Vaclav Kotesovec, Feb 08 2020

A349105 Expansion of e.g.f. 1/(1 - (sinh(x) + x*cosh(x))/2 ).

Original entry on oeis.org

1, 1, 2, 8, 40, 243, 1796, 15502, 152608, 1690613, 20814208, 281859540, 4163795648, 66636761575, 1148477490304, 21207704998010, 417728195909632, 8742243282090153, 193720478508563456, 4531158728871170080, 111562803180301643776, 2884156736234559267611
Offset: 0

Views

Author

Seiichi Manyama, Mar 26 2022

Keywords

Crossrefs

Programs

  • Mathematica
    With[{m = 21}, Range[0, m]! * CoefficientList[Series[1/(1 - (Sinh[x] + x*Cosh[x])/2), {x, 0, m}], x]] (* Amiram Eldar, Mar 26 2022 *)
  • PARI
    my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-(sinh(x)+x*cosh(x))/2)))
    
  • PARI
    a(n) = if(n==0, 1, sum(k=0, (n-1)\2, (k+1)*binomial(n, 2*k+1)*a(n-2*k-1)));

Formula

a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/2)} (k+1) * binomial(n,2*k+1) * a(n-2*k-1).

A352251 Expansion of e.g.f. 1 / (1 - x * sinh(x)) (even powers only).

Original entry on oeis.org

1, 2, 28, 966, 62280, 6452650, 980531916, 205438870014, 56760128400016, 19994672935658322, 8746764024725937300, 4651991306703670964518, 2956156902003429777549144, 2212026607642404922284728826, 1925137044528752884360406444380, 1928103808741894922401976601295950
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 09 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 30; Take[CoefficientList[Series[1/(1 - x Sinh[x]), {x, 0, nmax}], x] Range[0, nmax]!, {1, -1, 2}]
    a[0] = 1; a[n_] := a[n] = 2 Sum[Binomial[2 n, 2 k] k a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 15}]
  • PARI
    my(x='x+O('x^40), v=Vec(serlaplace(1 /(1-x*sinh(x))))); vector(#v\2, k, v[2*k-1]) \\ Michel Marcus, Mar 10 2022

Formula

a(0) = 1; a(n) = 2 * Sum_{k=1..n} binomial(2*n,2*k) * k * a(n-k).

A352326 Expansion of e.g.f.: 1/(2 - exp(x) - sinh(x)).

Original entry on oeis.org

1, 2, 9, 62, 567, 6482, 88929, 1423382, 26037027, 535813802, 12251630349, 308153112302, 8455276083087, 251333936555522, 8045613346221369, 275950004166050822, 10095559110771678747, 392427366313299119642, 16151459739717643489989
Offset: 0

Views

Author

Seiichi Manyama, Mar 12 2022

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; `if`(n=0, 1, add(
          a(n-k)*binomial(n, k)*(1+(k mod 2)), k=1..n))
        end:
    seq(a(n), n=0..18); # Alois P. Heinz, Mar 25 2022
  • Mathematica
    m = 18; Range[0, m]! * CoefficientList[Series[1/(2 - Exp[x] - Sinh[x]), {x, 0, m}], x] (* Amiram Eldar, Mar 12 2022 *)
  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(2-exp(x)-sinh(x))))
    
  • PARI
    a(n) = if(n==0, 1, sum(k=1, n, (3-(-1)^k)/2*binomial(n, k)*a(n-k)));

Formula

a(0) = 1; a(n) = Sum_{k=1..n} (3-(-1)^k)/2 * binomial(n,k) * a(n-k).
a(n) ~ n! / (sqrt(7) * log((2 + sqrt(7))/3)^(n+1)). - Vaclav Kotesovec, Mar 12 2022

A352327 Expansion of e.g.f.: 1/(3 - exp(x) - cosh(x)).

Original entry on oeis.org

1, 1, 4, 19, 130, 1081, 10894, 127639, 1711210, 25798141, 432212134, 7964801659, 160121522290, 3487254825601, 81790592435374, 2055350489070079, 55093108433421370, 1569052795651631461, 47315282424232826614, 1506074331671551028899
Offset: 0

Views

Author

Seiichi Manyama, Mar 12 2022

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; `if`(n=0, 1, add(
          a(n-k)*binomial(n, k)*(2-(k mod 2)), k=1..n))
        end:
    seq(a(n), n=0..19); # Alois P. Heinz, Mar 25 2022
  • Mathematica
    m = 19; Range[0, m]! * CoefficientList[Series[1/(3 - Exp[x] - Cosh[x]), {x, 0, m}], x] (* Amiram Eldar, Mar 12 2022 *)
  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(3-exp(x)-cosh(x))))
    
  • PARI
    a(n) = if(n==0, 1, sum(k=1, n, (3+(-1)^k)/2*binomial(n, k)*a(n-k)));

Formula

a(0) = 1; a(n) = Sum_{k=1..n} (3+(-1)^k)/2 * binomial(n,k) * a(n-k).
a(n) ~ n! / (sqrt(6) * log(1 + sqrt(2/3))^(n+1)). - Vaclav Kotesovec, Mar 12 2022

A352428 a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n,3*k+1) * a(n-3*k-1).

Original entry on oeis.org

1, 1, 2, 6, 25, 130, 810, 5881, 48806, 455706, 4727881, 53955682, 671730246, 9059714665, 131588822822, 2047796305470, 33992509701721, 599526848094850, 11195864285933682, 220692569175568729, 4579248276057441926, 99767702172338210898, 2277136869014579978473, 54336724559407913237122
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 16 2022

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, 3 k + 1] a[n - 3 k - 1], {k, 0, Floor[(n - 1)/3]}]; Table[a[n], {n, 0, 23}]
    nmax = 23; CoefficientList[Series[1/(1 - Sum[x^(3 k + 1)/(3 k + 1)!, {k, 0, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\3, x^(3*k+1)/(3*k+1)!)))) \\ Seiichi Manyama, Mar 23 2022

Formula

E.g.f.: 1 / (1 - Sum_{k>=0} x^(3*k+1) / (3*k+1)!).

A352430 a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/5)} binomial(n,5*k+1) * a(n-5*k-1).

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 721, 5054, 40488, 364896, 3654000, 40249441, 483659508, 6296246424, 88269037584, 1325861901000, 21243052172161, 361630022931666, 6518319228715302, 124018898163736536, 2483799332459535000, 52231733840672804881, 1150683180739820615582, 26502219276887376327696
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 16 2022

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, 5 k + 1] a[n - 5 k - 1], {k, 0, Floor[(n - 1)/5]}]; Table[a[n], {n, 0, 23}]
    nmax = 23; CoefficientList[Series[1/(1 - Sum[x^(5 k + 1)/(5 k + 1)!, {k, 0, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\5, x^(5*k+1)/(5*k+1)!)))) \\ Seiichi Manyama, Mar 23 2022

Formula

E.g.f.: 1 / (1 - Sum_{k>=0} x^(5*k+1) / (5*k+1)!).

A365915 Expansion of e.g.f. 1 / ( 1 - Sum_{k>=0} x^(2*k+5) / (2*k+5)! ).

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 252, 1, 1584, 1, 7436, 756757, 31616, 14702689, 129404, 189559657, 11733266992, 2062481617, 516242875084, 20611819933, 14135172627712, 623557476714481, 312148517693820, 52096977907924561, 6121122865591920
Offset: 0

Views

Author

Seiichi Manyama, Sep 23 2023

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+x+x^3/6-sinh(x))))

Formula

a(0) = 1; a(n) = Sum_{k=0..floor((n-5)/2)} binomial(n,2*k+5) * a(n-2*k-5).
E.g.f.: 1 / ( 1 + x + x^3/6 - sinh(x) ).
Previous Showing 21-30 of 45 results. Next