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A364359 Primes that are the concatenation of a square and a prime that is the concatenation of two squares.

%I A364359 #13 Oct 21 2023 05:49:19
%S A364359 419,911,919,941,1181,1499,1619,1811,4919,8111,9181,9491,9811,11699,
%T A364359 12119,12251,14411,14419,16481,16811,19001,22511,22541,32411,32441,
%U A364359 36251,44111,44119,44729,49499,49811,52919,57641,64499,64811,67619,72911,81181,90011,90019,91009,92251,94441,97841,98419
%N A364359 Primes that are the concatenation of a square and a prime that is the concatenation of two squares.
%C A364359 Primes that are the concatenation of a square and a member of A167535.
%H A364359 Robert Israel, <a href="/A364359/b364359.txt">Table of n, a(n) for n = 1..10000</a>
%e A364359 a(5) = 1181 is a term because it is the concatenation of 1^2 = 1, 1^2 =1 and 9^2 = 81, and 181 and 1181 are primes.
%p A364359 for d from 1 to 3 do
%p A364359   m1:= ceil(10^((d-1)/2));
%p A364359   m2:= floor(sqrt(10^d - 1));
%p A364359   S[d]:= {seq(i^2, i=m1..m2)};
%p A364359   if m1::even then m1:= m1+1 fi;
%p A364359   So[d]:= {seq(i^2, i=m1..m2,2)};
%p A364359 od:
%p A364359 for d from 2 to 4 do P2[d]:= select(isprime, {seq(seq(seq(10^i*s+t, t=So[i]),s=S[d-i]),i=1..d-1)}) od:
%p A364359 for d from 3 to 5 do P3[d]:= select(isprime, {seq(seq(seq(10^i*s+t, t=P2[i]),s=S[d-i]),i=2..d-1)}) od:
%p A364359 sort([seq](op(P3[d]),d=3..5));
%Y A364359 Cf. A167535.
%K A364359 nonn,base
%O A364359 1,1
%A A364359 _Robert Israel_, Oct 20 2023