%I #13 Oct 14 2017 14:55:47
%S 1,49,121,169,361,529,1849,2401,3721,6241,8281,9409,11881,14161,14641,
%T 19321,20449,25921,27889,39601,49729,51529,52441,69169,76729,83521,
%U 89401,94249,104329,113569,124609,143641,165649,175561,187489,190969
%N Squares that becomes primes when prefixed with a 3.
%H G. C. Greubel, <a href="/A167718/b167718.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[1, 4000, 2]^2, PrimeQ[FromDigits[Join[{3}, IntegerDigits[#]]]] &] (* _G. C. Greubel_, Jun 21 2016 *)
%K base,nonn
%O 1,2
%A _Claudio Meller_, Nov 10 2009
%E Definition modified by _Harvey P. Dale_, Oct 14 2017