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 A167724 #7 Jun 22 2016 03:05:44
%S A167724 1369,2401,2809,3481,5929,9409,10201,14161,16129,17689,25921,28561,
%T A167724 32761,41209,44521,64009,94249,100489,108241,116281,117649,130321,
%U A167724 137641,146689,157609,170569,175561,177241,196249,201601,218089,219961
%N A167724 Squares that becomes a prime number when prefixed with a 9.
%C A167724 Subsequence of squares of A032672. - _Michel Marcus_, Jun 22 2016
%H A167724 G. C. Greubel, <a href="/A167724/b167724.txt">Table of n, a(n) for n = 1..10000</a>
%t A167724 Select[Range[1, 500000, 2]^2, PrimeQ[FromDigits[Join[{9}, IntegerDigits[#]]]] &] (* _G. C. Greubel_, Jun 21 2016 *)
%Y A167724 Cf. A032672.
%K A167724 base,nonn
%O A167724 1,1
%A A167724 _Claudio Meller_, Nov 10 2009