OFFSET
0,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (32,-139,108).
FORMULA
G.f.: (3 - 64*x + 139*x^2)/((1 - x)*(1 - 4*x)*(1 - 27*x)).
a(n) = 32*a(n-1) - 139*a(n-2) + 108*a(n-3) for n > 2.
a(n) = 1 + 4^n + 27^n.
MATHEMATICA
Table[1 + 4^n + 27^n, {n, 0, 20}] (* Bruno Berselli, Mar 15 2017 *)
CoefficientList[Series[(3 - 64*x + 139*x^2)/((1 - x)*(1 - 4*x)*(1 - 27*x)), {x, 0, 17}], x] (* Indranil Ghosh, Mar 15 2017 *)
PROG
(PARI) Vec((3 - 64*x + 139*x^2)/((1 - x)*(1 - 4*x)*(1 - 27*x)) + O(x^17)) \\ Indranil Ghosh, Mar 15 2017
(PARI) a(n) = 1 + 4^n + 27^n \\ Indranil Ghosh, Mar 15 2017
(Python) def A283716(n): return 1 + 4**n + 27**n # Indranil Ghosh, Mar 15 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Mar 15 2017
EXTENSIONS
Extended by Bruno Berselli, Mar 15 2017
STATUS
approved