A171479 a(n) = 6*a(n-1)-8*a(n-2)+3 for n > 1; a(0) = 1, a(1) = 8.

1, 8, 43, 197, 841, 3473, 14113, 56897, 228481, 915713, 3666433, 14672897, 58705921, 234852353, 939466753, 3757981697, 15032156161, 60129083393, 240517251073, 962070839297, 3848287027201, 15393155448833, 61572636475393

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (7,-14,8)

Formula

a(n) = (2-7*2^n+7*4^n)/2.

G.f.: (1+x+x^2)/((1-x)*(1-2*x)*(1-4*x)).

Maple

A171479:=n->(2-7*2^n+7*4^n)/2: seq(A171479(n), n=0..30); # Wesley Ivan Hurt, Apr 28 2017

Mathematica

LinearRecurrence[{7, -14, 8}, {1, 8, 43}, 30] (* Harvey P. Dale, Sep 18 2022 *)

Prog

(PARI) {m=23; v=concat([1, 8], vector(m-2)); for(n=3, m, v[n]=6*v[n-1]-8*v[n-2]+3); v}
(Magma) [(2-7*2^n+7*4^n)/2: n in [0..30]]; // Vincenzo Librandi, Jul 18 2011

Crossrefs

Cf. A171472, A171473, A171478.

Sequence in context: A005024 A094865 A122880 * A227209 A282523 A099253

Adjacent sequences: A171476 A171477 A171478 * A171480 A171481 A171482

Keyword

nonn,easy

Author

Klaus Brockhaus, Dec 09 2009

Status

approved