OFFSET
0,1
LINKS
H. Shabani, Computing vertex PI index of tetrathiafulvalene dendrimers, Iranian J. Math. Chem., 1, 2010, 125-130.
FORMULA
a(n) = -64939 + 2^n*(-27280*n+344122) + 4^n*(215264*n-268088).
G.f.: (11095 + 213214*z - 244408*z^2 - 559488*z^3 - 4864*z^4)/((1-z)*(1-2*z)^2*(1-4*z)^2).
MAPLE
a := proc (n) options operator, arrow: -64939+2^n*(-27280*n+344122)+4^n*(215264*n-268088) end proc: seq(a(n), n = 0 .. 20);
MATHEMATICA
CoefficientList[Series[(11095 + 213214*x - 244408*x^2 - 559488*x^3 - 4864*x^4) / ((1-x)*(1-2*x)^2*(1-4*x)^2), {x, 0, 64}], x] (* _Georg Fischer, Aug 18 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jul 12 2013
STATUS
approved