A182461 a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=16 and a(1)=40.

16, 40, 88, 184, 376, 760, 1528, 3064, 6136, 12280, 24568, 49144, 98296, 196600, 393208, 786424, 1572856, 3145720, 6291448, 12582904, 25165816, 50331640, 100663288, 201326584, 402653176, 805306360, 1610612728, 3221225464, 6442450936, 12884901880

Offset

0,1

Comments

Number of vertices into building blocks of 3d objects with 4 vertices.

Links

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

Index entries for linear recurrences with constant coefficients, signature (3, -2).

Formula

a(n) = a(n-1)*2 + 8.

G.f.: 16 + 40*x + 88*x^2 + 184*x^3 + 376*x^4 + 760*x^5 + 1528*x^6 + ...

a(n) = 8 * A055010(n+1). [Joerg Arndt, Jun 01 2014]

G.f.: -((8*(x - 2))/(2*x^2 - 3*x + 1)). - Vincenzo Librandi, Jun 02 2014

Example

a(0) = 4+8+4;
a(1) = 4+8+16+8+4;
a(2) = 4+8+16+32+16+8+4;
a(3) = 4+8+16+32+64+32+16+8+4.

Mathematica

CoefficientList[Series[-((8 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)

Crossrefs

Cf. A000045, A028399, A038578, A089143, A173033, A182462, A182464, A182465, A182466, A182467.

Sequence in context: A086046 A184030 A350284 * A205065 A368078 A185790

Adjacent sequences: A182458 A182459 A182460 * A182462 A182463 A182464

Keyword

nonn,easy

Author

Odimar Fabeny, Apr 30 2012

Status

approved