OFFSET
1,1
COMMENTS
The denominator is always 5.
LINKS
Index entries for linear recurrences with constant coefficients, signature (36,-128).
FORMULA
a(n) = -20 * 4^(n-1) + 64 * 2^(5*n-5) for n >= 1.
G.f.: 4*x*(11+96*x) / ( (32*x-1)*(4*x-1) ). - R. J. Mathar, Feb 04 2021
MATHEMATICA
f[n_] := (-Integrate[1 - x^(3/2), {x, 0, 4^n}])5; Table[ f[n], {n, 15}] (* Robert G. Wilson v, Sep 02 2004 *)
Table[- 20 4^(n - 1) + 64 2^(5 n - 5), {n, 20}] (* Vincenzo Librandi, Jul 25 2015 *)
LinearRecurrence[{36, -128}, {44, 1968}, 20] (* Harvey P. Dale, Feb 10 2022 *)
PROG
(PARI) for(n=1, 15, print1(64*2^(5*n-5)-20*4^(n-1), ", "))
(Magma) [-20*4^(n-1)+64*2^(5*n-5): n in [1..20]]; // Vincenzo Librandi, Jul 25 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Al Hakanson (Hawkuu(AT)excite.com), Jun 05 2004
EXTENSIONS
Edited by Rick L. Shepherd, Jun 06 2004
STATUS
approved