A177844 a(n) = 6*a(n-1)-8*a(n-2) for n > 3; a(0)=279, a(1)=3996, a(2)=16008, a(3)=64784.

279, 3996, 16008, 64784, 260640, 1045568, 4188288, 16765184, 67084800, 268387328, 1073645568, 4294774784, 17179484160, 68718706688, 274876366848, 1099508547584, 4398040350720, 17592173723648, 70368719536128

Offset: 0

Author

Klaus Brockhaus, May 14 2010

Keywords

• nonn
• easy

Comments

Related to Reverse and Add trajectory of 775 in base 2: a(n) = A077077(4*n+1)/6, i.e. one sixth of second quadrisection of A077077.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (6, -8).

Crossrefs

Cf. A077077 (Reverse and Add trajectory of 775 in base 2), A177843, A177845, A177846.

Programs

Magma

[279, 3996] cat [4^(n+5)-47*2^(n+1): n in [2..25]]; // Vincenzo Librandi, Sep 24 2013

Mathematica

CoefficientList[Series[(279 + 2322 x - 5736 x^2 + 704 x^3)/((1 - 2 x) (1 - 4 x)), {x, 0, 40}], x] (* Vincenzo Librandi, Sep 24 2013 *)

PARI

{m=19; v=concat([279, 3996, 16008, 64784], vector(m-4)); for(n=5, m, v[n]=6*v[n-1]-8*v[n-2]); v}

Formula

a(n) = 4^(n+5)-47*2^(n+1) for n > 1.

G.f.: (279+2322*x-5736*x^2+704*x^3) / ((1-2*x)*(1-4*x)).

G.f. for the sequence starting at a(2): 8*x^2*(2001-3908*x)/((1-2*x)*(1-4*x)).