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 A262926 #14 Oct 05 2015 10:09:52
%S A262926 0,1,31,3408,873580,405071029,295716738515,312086923732368,
%T A262926 449317984129326216,846136323944158864793,2018612200059553898143707,
%U A262926 5949463230586042065279268128,21227845340442717633531647231668,90172805592203250075964230466892813
%N A262926 Sum of n consecutive n-th powers starting with n^n.
%e A262926 a(3) = 3^3 + 4^4 + 5^5 = 3408.
%t A262926 Table[Sum[k^k, {k, n, 2 n - 1}], {n, 0, 13}] (* _Michael De Vlieger_, Oct 05 2015 *)
%o A262926 (PARI) vector(20, n, n--; sum(k=n, 2*n-1, k^k))
%o A262926 (Sage) [sum(k^k for k in (n..2*n-1)) for n in (0..20)] # _Bruno Berselli_, Oct 05 2015
%Y A262926 Cf. A050410, A240137, A262925.
%K A262926 nonn,easy
%O A262926 0,3
%A A262926 _Colin Barker_, Oct 04 2015