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A088136
Primes such that sum of first and last digits is prime.
12
11, 23, 29, 41, 43, 47, 61, 67, 83, 89, 101, 131, 151, 181, 191, 211, 223, 229, 233, 239, 241, 251, 263, 269, 271, 281, 283, 293, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 601, 607, 617, 631, 641, 647, 661, 677, 691
OFFSET
1,1
LINKS
MATHEMATICA
Select[Prime[Range[400]], PrimeQ[First[IntegerDigits[#]]+ Last[ IntegerDigits[ #]]]&] (* Harvey P. Dale, Jun 23 2017 *)
PROG
(Python)
from sympy import isprime, primerange
def ok(p): s = str(p); return isprime(int(s[0]) + int(s[-1]))
def aupto(limit): return [p for p in primerange(1, limit+1) if ok(p)]
print(aupto(691)) # Michael S. Branicky, Nov 23 2021
(PARI) select( {is_A088136(p)=isprime(p\10^logint(p, 10)+p%10)&&isprime(p)}, primes(99)) \\ M. F. Hasler, Apr 23 2024
CROSSREFS
Cf. A008040 (primes), A010051 (isprime), A000030 (first digit of n), A010879 (last digit of n).
Sequence in context: A054723 A109981 A091367 * A164932 A086244 A091939
KEYWORD
easy,nonn,base
AUTHOR
Zak Seidov, Sep 20 2003
STATUS
approved