OFFSET
1,3
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537
FORMULA
MATHEMATICA
s[n_] := Module[{m = 1}, While[!Divisible[m*(m + 1), n], m++]; m]; f[p_, e_] := p^e - 1; uphi[n_] := Times @@ f @@@ FactorInteger[n]; uphi[1] = 1; a[n_] := GCD[uphi[n], s[n]]; Array[a, 100] (* Amiram Eldar, Jun 16 2022 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 16 2022
STATUS
approved