OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (4).
FORMULA
a(n) = A002001(n), n>1. - R. J. Mathar, Aug 18 2008
G.f.: 4*x*(1 - x)/(1 - 4*x). - Vincenzo Librandi, May 29 2014
MAPLE
seq(coeff(series(4*x*(1-x)/(1-4*x), x, n+1), x, n), n = 1 .. 25); # Muniru A Asiru, Oct 21 2018
MATHEMATICA
CoefficientList[Series[4 (1 - x)/(1 - 4 x), {x, 0, 40}], x] (* Vincenzo Librandi, May 29 2014 *)
PROG
(Magma) [4] cat [3*4^(n-1): n in [2..30]]; // Vincenzo Librandi, May 29 2014
(PARI) x='x+O('x^50); Vec(4*x*(1 - x)/(1 - 4*x)) \\ G. C. Greubel, Sep 01 2017
(GAP) Concatenation([4], List([2..25], n->3*4^(n-1))); # Muniru A Asiru, Oct 21 2018
CROSSREFS
KEYWORD
easy,less,nonn
AUTHOR
Jonathan Vos Post, Jul 29 2005
EXTENSIONS
Definition corrected by R. J. Mathar, Aug 18 2008
STATUS
approved