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A355563 a(n) is the number of numbers that divide the sum of the digits of their n-th powers. 1

%I #6 Jul 14 2022 17:25:33

%S 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 23,13,11,17,15,10,16,18,18,10,13,10,17,15,16,19,12,20,19,20,17,19,21,

%U 14,27,15,18,16,16,20,10,14,20,15,11,17,23,14,15,14,19,15

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

%C Row lengths of A355370.

%o (Python)

%o def ok(k, n): return sum(map(int, str(k**n)))%k==0

%o def a(n):

%o d, lim = 1, 1

%o while lim < n*9*d: d, lim = d+1, lim*10

%o return sum(1 for k in range(1, lim+1) if ok(k, n))

%o print([a(n) for n in range(67)]) # _Michael S. Branicky_, Jul 07 2022

%Y Cf. A355370, A046019.

%K nonn,base

%O 0,2

%A _Mohammed Yaseen_, Jul 07 2022

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Last modified August 23 13:21 EDT 2024. Contains 375396 sequences. (Running on oeis4.)