OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..900
Index entries for linear recurrences with constant coefficients, signature (14,-24).
FORMULA
a(n) = (12^n - 2^n)/10 for n>0. [Zerinvary Lajos, Jun 05 2009]
a(n) = 2^n*(6^(n+1)-1)/5 = 14*a(n-1)-24*a(n-2). - Vincenzo Librandi, Oct 09 2011
a(n) = Sum_{i=0..n} 2^(n+i)*3^i. [Bruno Berselli, Aug 28 2013]
EXAMPLE
For n=6, a(6) = 2^6+2^7*3+2^8*3^2+2^9*3^3+2^10*3^4+2^11*3^5+2^12*3^6 = 3583168. [Bruno Berselli, Aug 28 2013]
MATHEMATICA
CoefficientList[Series[1/((1 - 2*x)*(1 - 12*x)), {x, 0, 20}], x] (* Wesley Ivan Hurt, Apr 08 2017 *)
PROG
(Sage) [(12^n - 2^n)/10 for n in range(1, 18)] # Zerinvary Lajos, Jun 05 2009
(Magma) [2^n*(6^(n+1)-1)/5: n in [0..20]]; // Vincenzo Librandi, Oct 09 2011
(PARI) Vec(1/((1-2*x)*(1-12*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
(Magma) [&+[2^(n+i)*3^i: i in [0..n]]: n in [0..20]]; // Bruno Berselli, Aug 28 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved