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A167218 Primes whose reversal - 1 is a square.

%I A167218 #13 Jun 13 2021 08:25:03
%S A167218 2,5,71,73,101,109,263,269,523,541,587,1061,1063,2089,2251,2273,2297,
%T A167218 2843,2861,5441,5477,5483,6203,6221,7129,7507,7937,10009,10163,10169,
%U A167218 10487,10691,20201,20693,22391,22769,24023,24877,26141,26171,26723
%N A167218 Primes whose reversal - 1 is a square.
%C A167218 The first digit of a(n) cannot be 3, 4, 8 or 9. - _Altug Alkan_, Dec 20 2015
%H A167218 Chai Wah Wu, <a href="/A167218/b167218.txt">Table of n, a(n) for n = 1..7256</a>
%e A167218 71 is prime and 17-1 = 16 = 4^2.
%o A167218 (Python)
%o A167218 from sympy import isprime
%o A167218 A167218_list, i, j = [], 0, 1
%o A167218 while j < 10**10:
%o A167218     p = int(str(j)[::-1])
%o A167218     if j % 10 and isprime(p):
%o A167218         A167218_list.append(p)
%o A167218     j += 2*i+1
%o A167218     i += 1
%o A167218 A167218_list = sorted(A167218_list) # _Chai Wah Wu_, Dec 20 2015
%o A167218 (PARI) lista(nn) = {forprime(p=2, nn, if (issquare(eval(concat(Vecrev(Str(p))))-1), print1(p, ", ")););} \\ _Michel Marcus_, Dec 20 2015
%Y A167218 Cf. A007488.
%K A167218 base,nonn
%O A167218 1,1
%A A167218 _Claudio Meller_, Oct 30 2009