%I A038893
%S A038893 3,5,7,17,37,41,43,47,59,67,79,83,89,101,109,127,131,151,
%T A038893 163,167,173,193,211,227,251,257,269,277,293,311,331,337,
%U A038893 353,373,379,383,419,421,457,461,463,467,479,487,499,503
%N A038893 21 is a square mod p.
%Y A038893 Sequence in context: A057476 A016041 A140797 this_sequence A075227 A064080 
               A112986
%Y A038893 Adjacent sequences: A038890 A038891 A038892 this_sequence A038894 A038895 
               A038896
%K A038893 nonn
%O A038893 1,1
%A A038893 N. J. A. Sloane (njas(AT)research.att.com).