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 A274306 #16 Oct 10 2016 05:14:30
%S A274306 1,5,325,105625,108265625,270772328125,1403954521328125,
%T A274306 13484983177356640625,220951449360988556640625,
%U A274306 5798870788479144669033203125,231960630409954265905997158203125,13584774319958971582784723570166015625
%N A274306 a(n) = Product_{k=1..n} (4*k^4+1).
%H A274306 Erhan Gürel, <a href="http://www.jstor.org/stable/10.4169/amer.math.monthly.123.6.597">On the Occurrence of Perfect Squares Among Values of Certain Polynomial Products</a>, The American Mathematical Monthly 123.6 (2016): 597-599.
%F A274306 a(n) ~ (1 + cosh(Pi)) * 2^(2*n + 2) * n^(4*n + 2) / exp(4*n). - _Vaclav Kotesovec_, Oct 10 2016
%t A274306 Table[Product[4*k^4+1, {k,1,n}], {n, 0, 15}] (* _Vaclav Kotesovec_, Oct 10 2016 *)
%o A274306 (PARI) a(n) = prod(k=1, n, 4*k^4+1); \\ _Michel Marcus_, Oct 10 2016
%Y A274306 For squares in this sequence see A274307.
%Y A274306 Cf. A255434.
%K A274306 nonn
%O A274306 0,2
%A A274306 _N. J. A. Sloane_, Jun 20 2016