OFFSET
1,4
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
a[n_] := BitXor[n, DivisorSigma[0, n]]; Array[a, 100] (* Amiram Eldar, Jul 08 2019 *)
PROG
(PARI) a(n)=bitxor(n, numdiv(n)); \\ Michel Marcus, Jul 08 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 28 2010
STATUS
approved