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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A272039 a(n) = 10*n^2 + 4*n + 1.

Original entry on oeis.org

1, 15, 49, 103, 177, 271, 385, 519, 673, 847, 1041, 1255, 1489, 1743, 2017, 2311, 2625, 2959, 3313, 3687, 4081, 4495, 4929, 5383, 5857, 6351, 6865, 7399, 7953, 8527, 9121, 9735, 10369, 11023, 11697, 12391, 13105, 13839, 14593, 15367, 16161, 16975, 17809, 18663, 19537
Offset: 0

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Author

Vincenzo Librandi, Apr 20 2016

Keywords

Comments

Polynomials from the table "Coefficients and roots of Ehrhart polynomials" in Beck et al. paper (see Links section):
. Cube: A000578;
. Cube minus corner: A004068;
. Prism: A002411;
. Octahedron: A005900;
. Square pyramid: A000330;
. Bypyramid: A006003;
. Unimodular tetrahedron: A000292;
. Fat tetrahedron: A167875;
. Cyclic(2,5), which has the same polynomial form of this sequence.
a(n) for n = 0, -1, 1, -2, 2, -3, 3, ... gives all x such that (5*x - 3)/2 is a square.
Squares in sequence: 1, 49, 1385329, 101263969, 2880599856289, ...
Is this 1 followed by A228219?

Crossrefs

Programs

  • Magma
    [10*n^2+4*n+1: n in [0..50]];
    
  • Mathematica
    Table[10 n^2 + 4 n + 1, {n, 0, 50}]
    LinearRecurrence[{3,-3,1},{1,15,49},50] (* Harvey P. Dale, Dec 26 2021 *)
  • PARI
    a(n)=10*n^2+4*n+1 \\ Charles R Greathouse IV, Jun 17 2017

Formula

O.g.f.: (1 + 12*x + 7*x^2)/(1 - x)^3.
E.g.f.: (1 + 14*x + 10*x^2)*exp(x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
a(n) = 2*A168668(n) + 1.

Extensions

Edited by Bruno Berselli, Apr 22 2016
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