OFFSET
0,1
COMMENTS
Number of vertices into building blocks of 3d objects with 6 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 + 12.
a(n) = 12*A153893(n). - Michel Marcus, Jun 01 2014
G.f.: -((12*(x-2))/(2*x^2-3*x+1)). - Vincenzo Librandi, Jun 01 2014
EXAMPLE
a(0) = 6+12+6;
a(1) = 6+12+24+12+6;
a(2) = 6+12+24+48+24+12+6;
a(3) = 6+12+24+48+96+48+24+12+6.
MATHEMATICA
CoefficientList[Series[-((12 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 01 2014 *)
LinearRecurrence[{3, -2}, {24, 60}, 40] (* Harvey P. Dale, May 27 2018 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Odimar Fabeny, Apr 30 2012
STATUS
approved