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 A278420 #7 Sep 08 2017 07:24:15 %S A278420 1,1,1,2,2,5,4,9,10,20,18,32,45,58,82,101,148,178,274,306,452,512,785, %T A278420 872,1258,1450,2061,2304,3274,3796,5108,6056,7954,9376,12200,14733, %U A278420 18500,22608,28004,34354,41905,51752,62122,77090,91764,114640,134560,167690 %N A278420 a(n) = (A278399(n)^2 + A278400(n)^2)/2. %H A278420 Vaclav Kotesovec, <a href="/A278420/b278420.txt">Table of n, a(n) for n = 0..10000</a> %F A278420 a(n) = A292042(n)^2 + A292043(n)^2. - _Vaclav Kotesovec_, Sep 08 2017 %t A278420 Abs[(QPochhammer[I, x] + O[x]^60)[[3]]]^2 / 2 %Y A278420 Cf. A278399, A278400, A292042, A292043. %K A278420 nonn %O A278420 0,4 %A A278420 _Vladimir Reshetnikov_, Nov 21 2016