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