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.

A228568 a(n) = 2^n*A056236(n).

Original entry on oeis.org

2, 8, 48, 320, 2176, 14848, 101376, 692224, 4726784, 32276480, 220397568, 1504968704, 10276569088, 70172803072, 479169871872, 3271976550400, 22342453428224, 152563815022592, 1041770892754944, 7113656621858816, 48575085832830976, 331691433687777280
Offset: 0

Views

Author

R. J. Mathar, Nov 10 2013

Keywords

Comments

Bhadouria et al. call this the 2-binomial transform of the 2-Lucas numbers.

Programs

  • PARI
    Vec(2*(1-4*x)/(1-8*x+8*x^2) + O(x^50)) \\ Colin Barker, Mar 16 2016

Formula

G.f.: 2*( 1-4*x ) / ( 1-8*x+8*x^2 ).
a(n) = 2*A084130(n).
From Colin Barker, Mar 16 2016: (Start)
a(n) = ((4-2*sqrt(2))^n+(2*(2+sqrt(2)))^n).
a(n) = 8*a(n-1)-8*a(n-2) for n>1.
(End)