OFFSET
1,2
LINKS
Ray Chandler, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (3, -3, 1, 0, 0, 0, 1, -3, 3, -1).
FORMULA
a(n)=floor(1/{(7+n^4)^(1/4)}), where {}=fractional part.
It appears that a(n)=3a(n-1)-3a(n-2)+a(n-3)+a(n-7)-3a(n-8)+3a(n-9)-a(n-10) for n>=13.
MATHEMATICA
p[n_]:=FractionalPart[(n^4+7)^(1/4)]; q[n_]:=Floor[1/p[n]];
Table[q[n], {n, 1, 80}]
FindLinearRecurrence[Table[q[n], {n, 1, 1000}]]
Join[{1, 5}, LinearRecurrence[{3, -3, 1, 0, 0, 0, 1, -3, 3, -1}, {15, 36, 71, 123, 196, 292, 416, 571, 760, 987}, 49]] (* Ray Chandler, Aug 02 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 18 2011
STATUS
approved