OFFSET
1,4
REFERENCES
Sequence proposed by Reg Allenby.
LINKS
Ray Chandler, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (0, 1, 0, 0, 0, 0, 0, 1, 0, -1).
FORMULA
For n >= 10, a(2n)-2n is 4-periodic with period [-7,-7,-5,-6] and a(2n+1) is 4-periodic with period [8,8,8,6]. - Benoit Cloitre, Jan 01 2013
MATHEMATICA
a[n_]:=a[n]=If[n<=3, 1, a[n-a[n-1]]+a[n-1 -a[n-3]]]; Array[a, 81] (* Ray Chandler, Aug 25 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved