A245743 Primes p such that p - d is also prime, where d is the largest digit of p.

41, 163, 181, 263, 401, 443, 463, 487, 563, 613, 653, 1021, 1381, 1433, 1613, 1663, 1831, 2141, 2243, 2281, 2441, 2663, 2851, 2887, 3041, 3463, 3613, 3623, 3643, 4133, 4363, 4463, 4603, 4643, 4663, 4801, 5281, 5563, 5581, 5653, 5821, 5851, 5857, 6043, 6053

Offset

1,1

Comments

The least significant digit of a(n) is either 1, 3 or 7. - Colin Barker, Aug 03 2014

The largest digit of a(n) is 2, 4, 6 or 8. - Robert Israel, Aug 03 2014

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

Example

263 is in the sequence because 263 - 6 = 257, which is prime.

Maple

filter:= n -> isprime(n) and isprime(n - max(convert(n, base, 10))):
select(filter, [$1..10^5]); # Robert Israel, Aug 03 2014

Prog

(PARI) select(p->isprime(p-vecsort(digits(p), , 4)[1]), primes(2000))
(Magma) [p: p in PrimesUpTo(7000) | IsPrime(p-d) where d is Max(Intseq(p))]; // Bruno Berselli, Jul 31 2014

Crossrefs

Cf. A245742, A245744, A245745.

Sequence in context: A141988 A347075 A158602 * A142839 A142912 A158626

Adjacent sequences: A245740 A245741 A245742 * A245744 A245745 A245746

Keyword

nonn,base

Author

Colin Barker, Jul 31 2014

Status

approved