A332040 - OEIS

%I #9 Feb 06 2020 00:48:01

%S 1,1,1,0,1,2,1,0,0,2,1,1,1,1,1,0,1,1,1,0,1,2,1,1,0,1,0,0,1,5,1,0,1,2,

%T 1,0,1,1,1,0,1,2,1,0,0,1,1,0,0,1,1,0,1,0,1,1,1,1,1,3,1,1,0,0,1,3,1,0,

%U 1,2,1,1,1,1,0,0,1,3,1,0,0,1,1,1,1,1,1

%N Number of integers whose exponential divisors sum to n.

%H Amiram Eldar, <a href="/A332040/b332040.txt">Table of n, a(n) for n = 1..10000</a>

%e a(6) = 2 since there are 2 solutions to esigma(x) = 6 (esigma is A051377): 4 and 6.

%t f[p_, e_] := DivisorSum[e, p^# &]; esigma[1] = 1; esigma[n_] := Times @@ f @@@ FactorInteger[n]; m = 100; v = Table[0, {m}]; Do[e = esigma[k]; If[e <= m, v[[e]]++], {k, 1, m}]; v

%Y Cf. A054973, A051377, A063974, A332036, A332038.

%K nonn

%O 1,6

%A _Amiram Eldar_, Feb 05 2020