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%I #9 Aug 12 2017 12:17:18
%S 2,13,31,79,97,103,113,163,173,193,227,257,277,311,331,613,643,653,
%T 673,683,709,719,739,769,811,821,881,907,937,947,967,977,997,1013,
%U 1033,1063,1093,1103,1123,1153,1163,1193,1213,1223
%N Primes such that sum of the first and last digits is a square.
%t fldsQ[n_]:=Module[{idn=IntegerDigits[n]},IntegerQ[Sqrt[ idn[[1]] + idn[[-1]]]]]; Select[Prime[Range[200]],fldsQ] (* _Harvey P. Dale_, Aug 12 2017 *)
%o (PARI) okdigs(n) = digs = digits(n); issquare(digs[1]+digs[#digs]);
%o isok(n) = isprime(n) && okdigs(n); \\ _Michel Marcus_, Oct 05 2013
%Y Cf. A088133, A088134, A088135, A088136.
%K easy,nonn,base
%O 1,1
%A _Zak Seidov_, Sep 20 2003