%I
%S 3,19,307,523,631,1171,1801,5563,8731,12781,16831,30097,53299,54181,
%T 56629,62011,63667,64063,66457,67411,67807,108127,118801,128413,
%U 130303,131059,160453,188677,192637,196597,300583,302851,357661
%N Primes whose digit reversal is a triangular number.
%H Harvey P. Dale, <a href="/A115705/b115705.txt">Table of n, a(n) for n = 1..400</a>
%e 307 is prime and 703=T(73).
%t Select[Prime[Range[20000]],OddQ[Sqrt[1+8IntegerReverse[#]]]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 01 2019 *)
%Y Cf. A115704.
%K nonn,base
%O 1,1
%A _Giovanni Resta_, Jan 31 2006
