OFFSET
1,1
COMMENTS
The first digit of a(n) cannot be 3, 4, 8 or 9. - Altug Alkan, Dec 20 2015
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..7256
EXAMPLE
71 is prime and 17-1 = 16 = 4^2.
PROG
(Python)
from sympy import isprime
A167218_list, i, j = [], 0, 1
while j < 10**10:
p = int(str(j)[::-1])
if j % 10 and isprime(p):
A167218_list.append(p)
j += 2*i+1
i += 1
(PARI) lista(nn) = {forprime(p=2, nn, if (issquare(eval(concat(Vecrev(Str(p))))-1), print1(p, ", ")); ); } \\ Michel Marcus, Dec 20 2015
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Claudio Meller, Oct 30 2009
STATUS
approved