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%I #13 May 06 2020 15:42:54
%S 1,2,3,1,5,2,7,1,1,2,11,1,13,2,1,1,17,2,19,1,3,2,23,1,1,2,1,1,29,2,31,
%T 1,1,2,1,1,37,2,3,1,41,2,43,1,1,2,47,1,1,2,1,1,53,2,1,1,3,2,59,1,61,2,
%U 1,1,1,2,67,1,1,2,71,1,73,2,3,1,1,2,79,1,1,2,83,1,1
%N a(n) = n/A055032(n).
%C It is conjectured that this is n iff n is 1 or a prime.
%D R. K. Guy, Unsolved Problems Number Theory, A17.
%H Indranil Ghosh, <a href="/A055023/b055023.txt">Table of n, a(n) for n = 1..1000</a>
%t Table[n/Denominator[(Sum[m^(n - 1), {m, n - 1}] + 1)/n], {n, 10}] (* _Indranil Ghosh_, May 17 2017 *)
%o (PARI) a(n) = n/denominator((sum(m=1, n - 1, m^(n - 1)) + 1)/n); \\ _Indranil Ghosh_, May 17 2017
%o (Python)
%o from sympy import Integer
%o def a(n): return Integer(n)/((sum(m**(n - 1) for m in range(1, n)) + 1)/Integer(n)).denominator() # _Indranil Ghosh_, May 17 2017
%Y Cf. A055030, A055031, A055032, A201560, A204187.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Jun 11 2000
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