OFFSET
1,4
COMMENTS
An alternative definition (with A027751) would define a(1)=1. - R. J. Mathar, Jul 14 2013
However, this definition is more aligned with A001065 and A218403 where the initial term a(1) is also 0. - Antti Karttunen, Oct 08 2017
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16383
FORMULA
MATHEMATICA
Array[BitXor @@ Most@ Divisors@ # &, 79] (* Michael De Vlieger, Oct 08 2017 *)
PROG
(PARI) A227320(n) = { my(s=0); fordiv(n, d, if(d<n, s = bitxor(s, d))); s; }; \\ Antti Karttunen, Oct 08 2017
CROSSREFS
KEYWORD
AUTHOR
Alex Ratushnyak, Jul 06 2013
STATUS
approved