A338190 - OEIS

%I #5 Oct 15 2020 10:51:56

%S 1,2,3,4,5,6,7,8,9,10,11,13,14,15,16,17,18,19,22,23,25,26,27,29,30,31,

%T 32,34,36,37,38,39,41,43,45,46,47,49,50,51,53,54,58,59,61,62,64,67,71,

%U 73,74,75,78,79,81,82,83,85,86,87,89,90,91,94,97,98,99,101,102

%N Integers m such that A337454(m) = tau(m), the number of divisors of n.

%o (PARI) f(n) = sumdiv(n, d, n % (sum(m=0, n-1, Mod(m, n)^d == m)/sum(m=0, n-1, -Mod(m, n)^d == m)) == 0); \\ A337454

%o isok(n) = f(n) == numdiv(n);

%Y Cf. A000005, A337454, A338189.

%K nonn

%O 1,2

%A _Michel Marcus_, Oct 15 2020