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.

A053297 Row sums of array T in A053199.

Original entry on oeis.org

1, 5, 22, 92, 372, 1468, 5688, 21728, 82064, 307088, 1140320, 4206912, 15434048, 56350912, 204875648, 742104064, 2679197952, 9644109056, 34623075840, 124001176576, 443136848896, 1580464036864, 5626501838848, 19996918849536, 70960191213568, 251445325991936
Offset: 1

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Author

Clark Kimberling, Mar 18 2000

Keywords

Comments

The generating series is a power series composition G(F(t)) where F(t) = t + 3*t^2 + 7*t^3 + 15*t^4 + ... is generating series of A000225, and G(t) = t + 2*t^2 + 3*t^3 + 4*t^4 + ... is generating series of the natural numbers A000027. Proof follows as in reference below. - Oboifeng Dira, Nov 03 2016

Examples

			G.f. = x + 5*x^2 + 22*x^3 + 92*x^4 + 372*x^5 + 1468*x^6 + 5688*x^7 + 21728*x^8 + ...
		

Crossrefs

Programs

  • Magma
    m:=25; R:=PowerSeriesRing(Integers(), m); Coefficients(R!(x*(1-x)*(1-2*x)/(1-4*x+2*x^2)^2)); // G. C. Greubel, May 24 2018
  • Mathematica
    Drop[CoefficientList[Series[x*(1-x)*(1-2*x)/(1-4*x+2*x^2)^2, {x,0,50}], x], 1] (* G. C. Greubel, May 24 2018 *)
  • PARI
    my(x='x+O('x^30)); Vec(x*(1-x)*(1-2*x)/(1-4*x+2*x^2)^2) \\ G. C. Greubel, May 24 2018
    

Formula

G.f.: x * (1 - x) * (1 - 2*x) / (1 - 4*x + 2*x^2)^2. - Michael Somos, Nov 03 2016
a(n) = 8*a(n-1) + 20*a(n-2) - 16*a(n-3) + 4*a(n-4) for all n in Z. - Michael Somos, Nov 03 2016
a(n) = -a(-n) * 2^n for all n in Z. - Michael Somos, Nov 03 2016