A245742 Primes p such that p + d is also prime, where d is the largest digit of p.

43, 61, 263, 461, 563, 601, 613, 641, 653, 683, 821, 1063, 1283, 1361, 1423, 1481, 1601, 1613, 1621, 1663, 1823, 1871, 2063, 2081, 2111, 2381, 2843, 3061, 3163, 3343, 3461, 3463, 3631, 3881, 4003, 4561, 4583, 4643, 4651, 5563, 5641, 5651, 5653, 5783, 5813

Offset

1,1

Comments

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

The largest digit of a(n) is 2, 4, 6 or 8. - Colin Barker, Aug 04 2014

Links

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

Example

263 is in the sequence because 263 + 6 = 269, which is prime.

Maple

select(p -> isprime(p) and isprime(p + max(convert(p, base, 10))), [$1..1000]); # 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. A245743, A245744, A245745.

Sequence in context: A129928 A317393 A253848 * A295702 A102269 A020349

Adjacent sequences: A245739 A245740 A245741 * A245743 A245744 A245745

Keyword

nonn,base

Author

Colin Barker, Jul 31 2014

Status

approved