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 A227783 #6 Jul 31 2013 13:36:35 %S A227783 1,2,2,2,2,4,2,2,2,2,4,2,2,2,2,4,2,2,2,4,2,2,2,2,2,4,2,2,2,2,4,2,2,4, %T A227783 2,2,2,2,2,2,2,2,2,2,4,2,2,2,2,4,2,2,2,2,4,2,2,2,2,4,2,2,2,4,2,2,2,2, %U A227783 2,4,2,2,2,2,4,2,2,4,2,2,2,2,2,2,2,2,2,2,4,2,2,2,4 %N A227783 Stufe of Q(sqrt(-k)), where k is the n-th squarefree number. %C A227783 A227782 is the main entry for this sequence. %H A227783 Charles R Greathouse IV, <a href="/A227783/b227783.txt">Table of n, a(n) for n = 1..10000</a> %F A227783 a(n) = A227782(A005117(n)). %o A227783 (PARI) apply(n->if(n%8==7,4,if(n>1,2,1)),select(issquarefree, vector(200,i,i))) %Y A227783 Cf. A227782, A227781. %K A227783 nonn,easy %O A227783 1,2 %A A227783 _Charles R Greathouse IV_, Jul 31 2013