OFFSET
0,1
COMMENTS
Number of vertices into building blocks of 3d objects with 5 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 + 10.
a(n) = 10*A153893(n). - Michel Marcus, Jun 01 2014
G.f.: -((10*(x - 2))/(2*x^2 - 3*x + 1)). - Vincenzo Librandi, Jun 02 2014
EXAMPLE
a(0) = 5+10+5;
a(1) = 5+10+20+10+5;
a(2) = 5+10+20+40+20+10+5;
a(3) = 5+10+20+40+80+40+20+10+5.
MATHEMATICA
CoefficientList[Series[-((10 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Odimar Fabeny, Apr 30 2012
STATUS
approved