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 A219550 #20 Nov 05 2017 11:52:39
%S A219550 3,260,53823,12942210875,11901444483396,25627001801054931008,
%T A219550 55413915436873048932459,490667517005738962388828685983,
%U A219550 48588952813858892791005036793649985985124,303307728036900627681487165427498812641117375,158544898951978777519612048992784361843596346824881328548
%N A219550 Sum(m^p, m=1..p-1)/p as p runs through the odd primes.
%C A219550 Always an integer: for an elementary proof that Sum(m^k,m=1..p-1)/p is an integer if p is prime and p-1 does not divide k (and a discussion of other proofs), see MacMillan and Sondow 2011. Applications are in Sondow and MacMillan 2011.
%C A219550 For (Sum(m^(p-1), m=1..p-1)+1)/p as p runs through the primes, see A055030.
%C A219550 For Sum(m^p, m=1..p-1) / p^2 as p runs through the odd primes, see A294507.
%H A219550 K. MacMillan and J. Sondow, <a href="http://arxiv.org/abs/1011.0076">Proofs of power sum and binomial coefficient congruences via Pascal's identity</a>, Amer. Math. Monthly, 118 (2011), 549-551.
%H A219550 J. Sondow and K. MacMillan, <a href="http://www.integers-ejcnt.org/l34/l34.pdf">Reducing the Erdos-Moser equation 1^n + 2^n + ... + k^n = (k+1)^n modulo k and k^2</a>, Integers 11 (2011), #A34.
%e A219550 a(1) = (1^3 + 2^3)/3 = (1 + 8)/3 = 3.
%t A219550 Array[Sum[m^#, {m, # - 1}]/# &@ Prime@ # &, 11, 2] (* _Michael De Vlieger_, Nov 04 2017 *)
%Y A219550 Cf. A055030, A294507.
%K A219550 nonn
%O A219550 1,1
%A A219550 _Jonathan Sondow_, Dec 04 2012