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 1-4 of 4 results.

A296439 Expansion of e.g.f. log(1 + arctanh(x))*exp(x).

Original entry on oeis.org

0, 1, 1, 4, 0, 53, -155, 2364, -15288, 216817, -2147215, 32932700, -433435816, 7431919285, -120703007451, 2326504612964, -44614898438480, 963118686971137, -21195404220321151, 508991484878443860, -12604990423335824688, 334199905021923072597, -9181752759370241656699, 266806716890671639953964
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 12 2017

Keywords

Examples

			E.g.f.: A(x) = x/1! + x^2/2! + 4*x^3/3! + 53*x^5/5! - 155*x^6/6! + 2364*x^7/7! - 15288*x^8/8! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(log(1+arctanh(x))*exp(x),x=0,24): seq(n!*coeff(a,x,n),n=0..23); # Paolo P. Lava, Mar 27 2019
  • Mathematica
    nmax = 23; CoefficientList[Series[Log[1 + ArcTanh[x]] Exp[x], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 23; CoefficientList[Series[Log[1 + (Log[1 + x] - Log[1 - x])/2] Exp[x], {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    my(ox=O(x^30)); Vecrev(Pol(serlaplace(log(1 + atanh(x + ox)) * exp(x + ox)))) \\ Andrew Howroyd, Dec 12 2017

Formula

E.g.f.: log(1 + (log(1 + x) - log(1 - x))/2)*exp(x).
a(n) ~ -(-1)^n * (n-1)! * exp((1-exp(2))/(1+exp(2))) * ((exp(2)+1)/(exp(2)-1))^n. - Vaclav Kotesovec, Dec 21 2017

A294314 Expansion of e.g.f. log(1 + x*sec(x))*exp(x).

Original entry on oeis.org

0, 1, 1, 5, 0, 64, -245, 2757, -23576, 272256, -3270977, 45055845, -671589952, 10984688636, -193875825117, 3688182769117, -75085512079184, 1630385857436224, -37596306847103457, 917765946045581357, -23641953753495247624, 640958728426947233468, -18242640219843554954221
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 27 2017

Keywords

Examples

			log(1 + x*sec(x))*exp(x) = x/1! + x^2/2! + 5*x^3/3! + 64*x^5/5! - 245*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(log(1+x*sec(x))*exp(x),x=0,23): seq(n!*coeff(a,x,n),n=0..22); # Paolo P. Lava, Mar 27 2019
  • Mathematica
    nmax = 22; CoefficientList[Series[Log[1 + x Sec[x]] Exp[x], {x, 0, nmax}], x] Range[0, nmax]!

A296336 Expansion of e.g.f. log(1 + x*cos(x))*exp(x).

Original entry on oeis.org

0, 1, 1, -1, 0, -16, -5, 13, -1512, 12336, -98177, 444773, 1249160, -75244508, 1296229779, -15956614403, 130892534160, 59122803744, -31478991643617, 837166840532589, -14900078660739984, 181343532181629332, -480411914937891389, -54306065912649098539, 2080183542455901881320
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 27 2017

Keywords

Examples

			log(1 + x*cos(x))*exp(x) = x/1! + x^2/2! - x^3/3! - 16*x^5/5! - 5*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(log(1 + x*cos(x))*exp(x),x=0,25): seq(n!*coeff(a,x,n),n=0..24); # Paolo P. Lava, Mar 27 2019
  • Mathematica
    nmax = 24; CoefficientList[Series[Log[1 + x Cos[x]] Exp[x], {x, 0, nmax}], x] Range[0, nmax]!
  • PARI
    x='x+O('x^99); concat([0], Vec(serlaplace(exp(x)*log(1+x*cos(x))))) \\ Altug Alkan, Dec 28 2017

A297211 Expansion of e.g.f. log(1 + arctan(x))*exp(-x).

Original entry on oeis.org

0, 1, -3, 6, -8, 13, -103, 462, 824, -8239, -147747, 1233518, 12148288, -127674419, -2090702391, 24495009510, 410685350032, -5514147250815, -111860639828131, 1673006899192118, 37306857729115304, -619246417449233555, -15476404474443728487, 281907759055194714206
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 27 2017

Keywords

Examples

			log(1 + arctan(x))*exp(-x) = x/1! - 3*x^2/2! + 6*x^3/3! - 8*x^4/4! + 13*x^5/5! - 103*x^6/6! + ...
		

Crossrefs

Programs

  • Maple
    a:=series(log(1+arctan(x))*exp(-x),x=0,24): seq(n!*coeff(a,x,n),n=0..23); # Paolo P. Lava, Mar 26 2019
  • Mathematica
    nmax = 23; CoefficientList[Series[Log[1 + ArcTan[x]] Exp[-x], {x, 0, nmax}], x] Range[0, nmax]!
    nmax = 23; CoefficientList[Series[Log[1 + (I/2) (Log[1 - I x] - Log[1 + I x])] Exp[-x], {x, 0, nmax}], x] Range[0, nmax]!
Showing 1-4 of 4 results.