OFFSET
0,1
COMMENTS
Related to Reverse and Add trajectory of 318 in base 4: A075153(6*n+5) = 240*a(n).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (20, -64).
FORMULA
a(n) = (256*16^n - 4^n)/3.
G.f.: (85 - 336*x)/((1-4*x)*(1-16*x)).
Limit_{n -> infinity} a(n)/a(n-1) = 16.
E.g.f.: (1/3)*(256*exp(16*x) - exp(4*x)). - G. C. Greubel, May 28 2016
MATHEMATICA
LinearRecurrence[{20, -64}, {85, 1364}, 50] (* G. C. Greubel, May 28 2016 *)
PROG
(PARI) {m=15; v=concat([85, 1364], vector(m-2)); for(n=3, m, v[n]=20*v[n-1]-64*v[n-2]); v}
(Magma)
[Binomial(4^(n+4), 2)/384: n in [0..30]]; // G. C. Greubel, Oct 02 2024
(SageMath)
A166917=BinaryRecurrenceSequence(20, -64, 85, 1364)
[A166917(n) for n in range(31)] # G. C. Greubel, Oct 02 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, Oct 27 2009
STATUS
approved