OFFSET
0,1
REFERENCES
I, Reiten, Dynkin diagrams and the representation theory of algebras, Notices of the AMS, Vol. 44, No 5.
FORMULA
a(n) = 6*(n+1) + 2*A087504(n).
G.f.: (6/(1-x)^2)+2*(1-x^9)/((1-x^4)*(1-x^6)*(1-x)).
MATHEMATICA
CoefficientList[ Series[ (8 + 6x + 6x^2 + 14x^3 + 6x^4 + 6x^5 + 8x^6) / (1 - x + x^3 - 2x^4 + x^5 - x^7 + x^8), {x, 0, 54}], x] (* Jean-François Alcover, Dec 02 2011 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Boddington, Jan 22 2004
STATUS
approved