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.

A329227 Products of consecutive terms of the Padovan sequence A000931.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 1, 2, 4, 6, 12, 20, 35, 63, 108, 192, 336, 588, 1036, 1813, 3185, 5590, 9804, 17214, 30200, 53000, 93015, 163215, 286440, 502656, 882096, 1547992, 2716504, 4767161, 8365777, 14680890, 25763220, 45211238, 79340228, 139232412, 244335771
Offset: 0

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Author

David Nacin, Nov 08 2019

Keywords

Examples

			For n=5, a(5) = A000931(5)*A000931(6) = 1*1.
		

Crossrefs

Programs

  • Mathematica
    Times@@@Partition[LinearRecurrence[{0,1,1},{1,0,0},50],2,1] (* Harvey P. Dale, Jul 05 2021 *)
  • Python
    p = lambda x:[1,0,0][x] if x<3 else p(x-2)+p(x-3)
    a = lambda x:p(x)*p(x+1)

Formula

a(n) = A000931(n)*A000931(n+1).
a(n+2) = Sum_{i=0..n} A000931(i)*A000931(i+2).
a(n) - a(n-2) - a(n-3) - a(n-4) = A133037(n-2) + A133037(n-3) for n>3.
G.f.: x^5 / ((1 - 2*x + x^2 - x^3)*(1 + x - x^3)) (conjectured). - Colin Barker, Nov 08 2019