OFFSET
1,1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..8264
MATHEMATICA
a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; Select[Range@ 144, EvenQ@ a[#] &] (* Michael De Vlieger, Mar 18 2017, after Robert G. Wilson v at A004001 *)
PROG
(Scheme, with Antti Karttunen's IntSeq-library)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 18 2017
STATUS
approved