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 1-7 of 7 results.

A009121 Expansion of e.g.f. cosh(exp(x)*x).

Original entry on oeis.org

1, 0, 1, 6, 25, 100, 481, 2954, 20721, 151848, 1146721, 9111982, 77652169, 710421452, 6891125697, 69961213170, 738718169569, 8108554524112, 92647353941569, 1101958783026134, 13616813607795321, 174287243264606388, 2304515271134124577, 31424734896799742170
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Magma
    m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cosh(x*Exp(x)))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 26 2018
  • Maple
    a:= n-> add(`if`(k::odd, 0, binomial(n, k)*k^(n-k)), k=0..n):
    seq(a(n), n=0..25);  # Alois P. Heinz, Jan 15 2018
  • Mathematica
    With[{nn=30},CoefficientList[Series[Cosh[Exp[x]*x],{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Dec 28 2015 *)
  • PARI
    first(n) = x='x+O('x^n); Vec(serlaplace(cosh(exp(x)*x))) \\ Iain Fox, Dec 23 2017
    

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997
Definition clarified and prior Mathematica program replaced by Harvey P. Dale, Dec 28 2015

A009448 E.g.f. sin(x*exp(x)).

Original entry on oeis.org

0, 1, 2, 2, -8, -84, -504, -2304, -6656, 15760, 484000, 5348320, 44393856, 288642368, 1137006976, -5372233216, -195241910272, -2961479980800, -34259767672320, -320473550808576, -2158264400250880, -1727938748171264, 278774033845987328
Offset: 0

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Author

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Crossrefs

Programs

  • Mathematica
    With[{nn=30},CoefficientList[Series[Sin[x Exp[x]],{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Mar 17 2012 *)
  • Maxima
    a(n):=sum(binomial(n,2*j+1)*(2*j+1)^(n-2*j-1)*(-1)^j,j,0,(n-1)/2); /* Vladimir Kruchinin, Jun 10 2011 */

Formula

a(n) = Sum_{j=0..(n-1)/2} binomial(n,2*j+1)*(2*j+1)^(n-2*j-1)*(-1)^j. - Vladimir Kruchinin, Jun 10 2011

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

A009768 Expansion of e.g.f. tanh(exp(x)*x).

Original entry on oeis.org

0, 1, 2, 1, -20, -159, -594, 2465, 69560, 665665, 1593850, -67177791, -1413216540, -12990964063, 64480265318, 4811655319393, 90259507840240, 540272971703937, -20890652777843598, -798235260367432831, -12766815370452348580
Offset: 0

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Crossrefs

Programs

  • Mathematica
    With[{nn=20},CoefficientList[Series[Tanh[Exp[x]*x],{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jun 03 2023 *)
  • PARI
    my(x='x+O('x^30)); concat(0, Vec(serlaplace(tanh(exp(x)*x)))) \\ Michel Marcus, Oct 01 2021

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997
Previous Mathematica program replaced by Harvey P. Dale, Jun 03 2023

A297009 Expansion of e.g.f. arcsin(x*exp(x)).

Original entry on oeis.org

0, 1, 2, 4, 16, 104, 816, 7792, 89216, 1177920, 17603200, 294334976, 5442281472, 110221745152, 2426850793472, 57718658411520, 1474590580228096, 40274407232294912, 1171043235561185280, 36115912820342407168, 1177554628069200035840, 40471207964013864124416
Offset: 0

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Author

Ilya Gutkovskiy, Dec 23 2017

Keywords

Examples

			arcsin(x*exp(x)) = x^1/1! + 2*x^2/2! + 4*x^3/3! + 16*x^4/4! + 104*x^5/5! + 816*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(arcsin(x*exp(x)),x=0,22): seq(n!*coeff(a,x,n),n=0..21); # Paolo P. Lava, Mar 26 2019
  • Mathematica
    nmax = 21; CoefficientList[Series[ArcSin[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 21; CoefficientList[Series[-I Log[I x Exp[x] + Sqrt[1 - x^2 Exp[2 x]]], {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    first(n) = my(x='x+O('x^n)); Vec(serlaplace(asin(exp(x)*x)), -n) \\ Iain Fox, Dec 23 2017

Formula

a(n) ~ sqrt(1 + LambertW(1)) * n^(n-1) / (exp(n) * LambertW(1)^n). - Vaclav Kotesovec, Mar 26 2019

A297010 Expansion of e.g.f. arcsinh(x*exp(x)).

Original entry on oeis.org

0, 1, 2, 2, -8, -76, -264, 1672, 36800, 261648, -1443680, -66164704, -792152448, 2482671424, 289529373056, 5294082629760, 1648955815936, -2474170098704128, -65494141255724544, -303927676523118080, 35926135133071923200, 1341060635191667045376
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 23 2017

Keywords

Examples

			arcsinh(x*exp(x)) = x^1/1! + 2*x^2/2! + 2*x^3/3! - 8*x^4/4! - 76*x^5/5! - 264*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(arcsinh(x*exp(x)),x=0,22): seq(n!*coeff(a,x,n),n=0..21); # Paolo P. Lava, Mar 26 2019
  • Mathematica
    nmax = 21; CoefficientList[Series[ArcSinh[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 21; CoefficientList[Series[Log[x Exp[x] + Sqrt[1 + x^2 Exp[2 x]]], {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    first(n) = my(x='x+O('x^n)); Vec(serlaplace(asinh(exp(x)*x)), -n) \\ Iain Fox, Dec 23 2017

A294312 Expansion of e.g.f. sec(x*exp(x)).

Original entry on oeis.org

1, 0, 1, 6, 29, 180, 1501, 14434, 154265, 1856232, 24953401, 368767102, 5936244533, 103519338780, 1944554725205, 39134556793050, 840024295910833, 19157944025344464, 462629389438242673, 11792248121970820598, 316398168231432879565, 8913743651504295251844
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 27 2017

Keywords

Examples

			sec(x*exp(x)) = 1 + x^2/2! + 6*x^3/3! + 29*x^4/4! + 180*x^5/5! + 1501*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(sec(x*exp(x)),x=0,22): seq(n!*coeff(a,x,n),n=0..21); # Paolo P. Lava, Mar 27 2019
  • Mathematica
    nmax = 21; CoefficientList[Series[Sec[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 21; CoefficientList[Series[1/Cos[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!

A294313 Expansion of e.g.f. sech(x*exp(x)).

Original entry on oeis.org

1, 0, -1, -6, -19, 20, 899, 7966, 27705, -366552, -8374201, -80690302, 9794597, 16015845820, 317370642315, 2554368906150, -37571987331343, -1784464543440304, -31315944840101233, -80221319702865398, 12685422355781995485, 422083364962616527716
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 27 2017

Keywords

Examples

			sech(x*exp(x)) = 1 - x^2/2! - 6*x^3/3! - 19*x^4/4! + 20*x^5/5! + 899*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(sech(x*exp(x)),x=0,22): seq(n!*coeff(a,x,n),n=0..21); # Paolo P. Lava, Mar 27 2019
  • Mathematica
    nmax = 21; CoefficientList[Series[Sech[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 21; CoefficientList[Series[1/Cosh[x Exp[x]], {x, 0, nmax}], x] Range[0, nmax]!
Showing 1-7 of 7 results.