A235149 Primes p such that (p reversed) + 7 is also a prime.

43, 61, 67, 229, 241, 271, 283, 409, 421, 439, 457, 601, 643, 661, 673, 2011, 2017, 2029, 2113, 2131, 2161, 2179, 2221, 2269, 2287, 2293, 2341, 2389, 2437, 2467, 2521, 2551, 2557, 2707, 2749, 2791, 2803, 2833, 2857, 4003, 4027, 4051, 4093, 4129, 4159, 4201, 4339, 4357

Offset: 1

Author

Vincenzo Librandi, Jan 04 2014

Keywords

• nonn
• base

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A165446, A166501, A167460, A167466, A167473.

Programs

Magma

[p: p in PrimesUpTo(6000) | IsPrime(q+7) where q is Seqint(Reverse(Intseq(p)))];

Mathematica

Select[Prime[Range[6000]], PrimeQ[FromDigits[Reverse[IntegerDigits[#]]] + 7]&]
Select[Prime[Range[600]],PrimeQ[IntegerReverse[#]+7]&] (* Harvey P. Dale, May 20 2023 *)