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 A178190 #14 Apr 11 2014 02:35:32
%S A178190 49,16856,40370463,678263443312,79792944561055313,
%T A178190 65712442156478841194856,378818757978106938161558820799,
%U A178190 15286701010761334171872123930835647200
%N A178190 Sum 7^((k^2+3k)/2) from k=1 to n.
%C A178190 Series of the kind m^((k^2+3k)/2) from k=1 to n was studied by Bernoulli and Euler.
%H A178190 Vincenzo Librandi, <a href="/A178190/b178190.txt">Table of n, a(n) for n = 1..40</a>
%p A178190 A178190:=n->add(7^((k^2 + 3*k)/2), k=1..n); seq(A178190(n), n=1..10); # _Wesley Ivan Hurt_, Apr 01 2014
%t A178190 aa = {}; m = 7; sum = 0; Do[sum = sum + m^((n + 3) n/2); AppendTo[aa, sum], {n, 1, 20}]; aa (* Artur Jasinski *)
%t A178190 Table[Sum[7^((k^2 + 3 k)/2), {k, n}], {n, 10}] (* _Wesley Ivan Hurt_, Apr 01 2014 *)
%o A178190 (PARI) a(n) = sum(k=1, n, 7^((k^2+3*k)/2)); \\ _Michel Marcus_, Sep 09 2013
%Y A178190 Cf. A178184-A178193.
%K A178190 nonn
%O A178190 1,1
%A A178190 _Artur Jasinski_, May 21 2010