OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (6,-5).
FORMULA
a(n) = A047848(2,n).
From Philippe Deléham, Oct 06 2009: (Start)
a(n) = 6*a(n-1) - 5*a(n-2) for n > 1.
G.f.: (1-4*x)/((1-x)*(1-5*x)). (End)
a(n) = 5*a(n-1) - 3 (with a(0)=1). - Vincenzo Librandi, Aug 06 2010
From Elmo R. Oliveira, Dec 10 2023: (Start)
a(n) = A132079(n)/2.
E.g.f.: (1/4)*(exp(5*x) + 3*exp(x)). (End)
MATHEMATICA
(5^Range[0, 40] +3)/4 (* G. C. Greubel, Jan 10 2025 *)
PROG
(PARI) a(n)=(5^n+3)/4 \\ Charles R Greathouse IV, Oct 07 2015
(Magma) A047850:= func< n | (5^n + 3)/4 >; [A047850(n): n in [0..40]]; // G. C. Greubel, Jan 10 2025
(Python)
def A047850(n): return (5^n+3)//4
print([A047850(n) for n in range(41)]) # G. C. Greubel, Jan 10 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Better description from Michael Somos
STATUS
approved