This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A055031 #18 Jun 26 2025 12:07:20
%S A055031 1,1,2,37,71,2213,9596,1200305,24684613,287152493,1355849266,
%T A055031 427675990237,1032458258547,228796942438201,16841089312342856,
%U A055031 665478473553144001,1653031004194447737,631449646252135295657,3167496749732497119310
%N A055031 Numerator of (Sum(m^(n-1),m=1..n-1)+1)/n.
%D A055031 R. K. Guy, Unsolved Problems Number Theory, A17.
%H A055031 Indranil Ghosh, <a href="/A055031/b055031.txt">Table of n, a(n) for n = 1..200</a>
%t A055031 Table[Numerator[(Sum[m^(n - 1), {m, n - 1}] + 1)/n], {n, 50}] (* _Indranil Ghosh_, May 17 2017 *)
%o A055031 (PARI) a(n) = numerator((sum(m=1, n - 1, m^(n - 1)) + 1)/n); \\ _Indranil Ghosh_, May 17 2017
%o A055031 (Python)
%o A055031 from sympy import Integer
%o A055031 def a(n): return ((sum(m**(n - 1) for m in range(1, n)) + 1)/Integer(n)).numerator # _Indranil Ghosh_, May 17 2017
%Y A055031 Cf. A055032, A055030, A055023, A201560, A204187.
%K A055031 nonn,frac
%O A055031 1,3
%A A055031 _N. J. A. Sloane_, Jun 11 2000