OFFSET
0,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (11,-34,24).
FORMULA
a(n) = 2 + 2*4^n + 6^n.
From Nathan L. Skirrow, Jun 25 2023: (Start)
G.f.: (5-39*x+64*x^2)/((1-x)*(1-4*x)*(1-6*x)).
E.g.f.: 2*e^x + 2*e^(4*x) + e^(6*x).
(End)
EXAMPLE
a(2) = 1^2 + 4^2 + 6^2 + 4^2 + 1^2 = 1 + 16 + 36 + 16 + 1 = 70.
MATHEMATICA
Table[6^n + 2*(4^n + 1), {n, 0, 24}] (* Amiram Eldar, May 27 2023 *)
PROG
(Python)
def A363299(n): return 2+(((1<<n+1)+3**n)<<n) # Chai Wah Wu, Jun 27 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
J. Lowell, May 26 2023
STATUS
approved