OFFSET
1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..67004
MATHEMATICA
a[n_] := Boole[Count[Divisors[n], _?(DivisorSigma[1, #] > 2*# &)] == 1]; Array[a, 100] (* Amiram Eldar, Mar 18 2024 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 14 2017
STATUS
approved