cp's OEIS Frontend

A355563 a(n) is the number of numbers that divide the sum of the digits of their n-th powers.

%I A355563 #6 Jul 14 2022 17:25:33
%S A355563 1,9,4,9,9,7,10,14,10,12,13,10,12,19,11,15,14,15,14,16,14,13,14,12,11,
%T A355563 23,13,11,17,15,10,16,18,18,10,13,10,17,15,16,19,12,20,19,20,17,19,21,
%U A355563 14,27,15,18,16,16,20,10,14,20,15,11,17,23,14,15,14,19,15
%N A355563 a(n) is the number of numbers that divide the sum of the digits of their n-th powers.
%C A355563 Row lengths of A355370.
%o A355563 (Python)
%o A355563 def ok(k, n): return sum(map(int, str(k**n)))%k==0
%o A355563 def a(n):
%o A355563     d, lim = 1, 1
%o A355563     while lim < n*9*d: d, lim = d+1, lim*10
%o A355563     return sum(1 for k in range(1, lim+1) if ok(k, n))
%o A355563 print([a(n) for n in range(67)]) # _Michael S. Branicky_, Jul 07 2022
%Y A355563 Cf. A355370, A046019.
%K A355563 nonn,base
%O A355563 0,2
%A A355563 _Mohammed Yaseen_, Jul 07 2022