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 A123723 #3 Mar 30 2012 17:37:54 %S A123723 1,4,8,12,20,28,44,45,52,63,68,76,92,116,124,126,148,164,172,175,188, %T A123723 212,236,244,268,284,292,316,332,350,356,388,404,412,428,436,452,508, %U A123723 524,548,556,596,604,628,652,668,692,716,724,764,772,788,796,844,892 %N A123723 Values of n for which A000224(n)=Ceiling[(n+1)/4], where A000224(n) is the number of squares mod n. %C A123723 Conjecture. If n>4 and a(n) is a multiple of 4, then a(n)/4 is a prime. (This has been verified up to n = 2000.) %Y A123723 Cf. A000224, A123722. %K A123723 nonn %O A123723 1,2 %A A123723 _John W. Layman_, Oct 12 2006