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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A301409 G.f. A(x) satisfies: A(x) = 1/(1 - x*A(x) - x^2*A(x)/(1 - 2*x*A(x) - 2*x^2*A(x)/(1 - 3*x*A(x) - 3*x^2*A(x)/(1 - ...)))), a continued fraction.

Original entry on oeis.org

1, 1, 3, 11, 47, 221, 1115, 5947, 33231, 193453, 1169239, 7322827, 47479855, 318661109, 2214609419, 15948123771, 119101155215, 923085573061, 7428862280327, 62094175343547, 538956428549743, 4854974080968669, 45347892277523467, 438688081755797051, 4389356528040108847
Offset: 0

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Author

Ilya Gutkovskiy, Mar 20 2018

Keywords

Examples

			G.f. A(x) = 1 + x + 3*x^2 + 11*x^3 + 47*x^4 + 221*x^5 + 1115*x^6 + 5947*x^7 + 33231*x^8 + ...
		

Crossrefs

A301412 G.f. A(x) satisfies: A(x) = 1/(1 - x*A(x)/(1 - x*A(x)/(1 - x^2*A(x)/(1 - x^2*A(x)/(1 - x^3*A(x)/(1 - x^3*A(x)/(1 - ...))))))), a continued fraction.

Original entry on oeis.org

1, 1, 3, 11, 46, 205, 957, 4614, 22803, 114898, 588052, 3048612, 15975922, 84489890, 450363757, 2417104782, 13050778500, 70841037919, 386357165119, 2116097719571, 11634392901981, 64188480019008, 355255552604237, 1971866447509917, 10973973061151433, 61222237473973758
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 20 2018

Keywords

Examples

			G.f. A(x) = 1 + x + 3*x^2 + 11*x^3 + 46*x^4 + 205*x^5 + 957*x^6 + 4614*x^7 + 22803*x^8 + 114898*x^9 + ...
		

Crossrefs

A301833 G.f. A(x) satisfies: A(x) = 1/(1 - 2*x*A(x)/(1 - 2*x*A(x)/(1 - 4*x*A(x)/(1 - 4*x*A(x)/(1 - 6*x*A(x)/(1 - 6*x*A(x)/(1 - ...))))))), a continued fraction.

Original entry on oeis.org

1, 2, 12, 104, 1104, 13472, 183488, 2749056, 44996864, 802443776, 15579089920, 329170937856, 7562372632576, 188526816632832, 5083702487990272, 147676990509580288, 4600624321049722880, 153012055369679241216, 5409813656756850262016, 202534832564335070937088, 8001606648308588124045312
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 27 2018

Keywords

Examples

			G.f. A(x) = 1 + 2*x + 12*x^2 + 104*x^3 + 1104*x^4 + 13472*x^5 + 183488*x^6 + 2749056*x^7 + 44996864*x^8 + ...
log(A(x)) = 2*x + 20*x^2/2 + 248*x^3/3 + 3472*x^4/4 + 53152*x^5/5 + 878144*x^6/6 + ... + A293471(n)*x^n/n + ...
		

Crossrefs

Programs

  • Mathematica
    Table[SeriesCoefficient[(1 + Sum[(2*k)!!*x^k, {k, 1, n}])^(n+1)/(n+1), {x, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Nov 05 2021 *)

Formula

a(n) = [x^n] (Sum_{k>=0} A000165(k)*x^k)^(n+1)/(n + 1).
a(n) ~ sqrt(Pi) * (2*n)^(n + 1/2) / exp(n-1). - Vaclav Kotesovec, Nov 05 2021
Previous Showing 11-13 of 13 results.