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.

A063092 a(0)=1, a(1)=2 and, for n>1, a(n) = a(n-1) + 11*a(n-2).

Original entry on oeis.org

1, 2, 13, 35, 178, 563, 2521, 8714, 36445, 132299, 533194, 1988483, 7853617, 29726930, 116116717, 443112947, 1720396834, 6594639251, 25519004425, 98060036186, 378769084861, 1457429482907, 5623889416378, 21655613728355, 83518397308513, 321730148320418
Offset: 0

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Author

John W. Layman, Apr 29 2003

Keywords

Comments

The binomial transform of this sequence is {(3^n)F(n+1)} where {F(n)} is the Fibonacci sequence A000045.

Crossrefs

Cf. A000045.

Programs

  • Mathematica
    LinearRecurrence[{1,11},{1,2},30] (* Harvey P. Dale, Oct 25 2020 *)
  • PARI
    { for (n=0, 200, if (n>1, a=a1 + 11*a2; a2=a1; a1=a, if (n, a=2; a2=1; a1=2, a=1)); write("b063092.txt", n, " ", a) ) } \\ Harry J. Smith, Aug 18 2009

Formula

G.f.: (1+x)/(1-x-11*x^2). - Jaume Oliver Lafont, Sep 07 2009
a(n) = A015447(n) + A015447(n-1), n>0. - Ralf Stephan, Jul 21 2013
a(n)^2 - (3*A015447(n-1))^2 - (3*A015447(n-1))*a(n) = (-11)^n. - Philippe Deléham, Mar 17 2023