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 A167723 #10 Nov 28 2016 02:42:38
%S A167723 9,81,2601,3969,4761,6561,25281,31329,35721,56169,59049,68121,71289,
%T A167723 91809,131769,149769,168921,194481,199809,210681,221841,263169,301401,
%U A167723 335241,370881,423801,439569,463761,480249,576081,603729,613089,622521
%N A167723 Squares that become prime numbers when prefixed with an 8.
%C A167723 Subsequence of squares of A032671. - _Michel Marcus_, Jun 22 2016
%H A167723 G. C. Greubel, <a href="/A167723/b167723.txt">Table of n, a(n) for n = 1..10000</a>
%t A167723 Select[Range[1, 500000, 2]^2, PrimeQ[FromDigits[Join[{8}, IntegerDigits[#]]]] &] (* _G. C. Greubel_, Jun 21 2016 *)
%Y A167723 Cf. A032671.
%K A167723 base,nonn
%O A167723 1,1
%A A167723 _Claudio Meller_, Nov 10 2009