OFFSET
5,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 5..1000
Robert Sedgewick, Analysis of shellsort and related algorithms, Fourth European Symposium on Algorithms, Barcelona, September, 1996.
Index entries for linear recurrences with constant coefficients, signature (3,-2).
FORMULA
G.f.: x^5*(1+2*x)*(1+14*x)/((1-x)*(1-2*x)). [Colin Barker, Mar 09 2012]
MATHEMATICA
LinearRecurrence[{3, -2}, {1, 19, 83}, 50] (* Paolo Xausa, Dec 03 2023 *)
PROG
(PARI) a(n)=if(n>5, 2^n-45, 1) \\ Charles R Greathouse IV, Mar 10 2012
(Python)
def a(n): return pow(2, n)-45 if n!= 5 else 1
for n in range(5, 100): print(a(n), end=', ') # Javier Rivera Romeu, Mar 04 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved