A178935 - OEIS

A178935

a(n) = floor((3*4^n - 2*3^n)/5).

0, 1, 6, 27, 121, 517, 2166, 8955, 36697, 149413, 605526, 2445723, 9853753, 39627589, 159148086, 638505531, 2559761689, 10256265445, 41076717846, 164461839579, 658312262905, 2634643765381, 10542759202806, 42183589235067, 168772014211801, 675201028661797

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: x*(1 - x - 3*x^2 + 4*x^3 - 7*x^4)/(1 - 7*x + 12*x^2 - x^4 + 7*x^5 - 12*x^6) = x*(1 - x - 3*x^2 + 4*x^3 - 7*x^4)/((1-3*x)*(1-4*x)*(1-x^4)).

Recurrence: a(n+6) = 7*a(n+5) - 12*a(n+4) + a(n+2) - 7*a(n+1) + 12*a(n).

PROG

(Maxima) makelist(floor((3*4^n-2*3^n)/5) , n, 0, 12);

(Magma) [Floor((3*4^n-2*3^n)/5): n in [0..30]]; // Vincenzo Librandi, Sep 06 2011

CROSSREFS