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A245745
Primes p such that p - d is also prime, where d is the smallest nonzero digit of p.
6
47, 67, 229, 283, 467, 523, 607, 647, 823, 829, 2029, 2083, 2089, 2239, 2269, 2383, 2593, 2659, 2689, 2803, 3253, 3259, 3529, 3823, 4007, 4243, 4273, 4423, 4723, 4787, 5023, 5233, 6047, 6079, 6679, 6709, 6829, 6869, 6967, 6977, 6997, 7687, 8089, 8233, 8293
OFFSET
1,1
COMMENTS
The least significant digit of a(n) is either 3, 7 or 9. - Colin Barker, Aug 03 2014
The smallest nonzero digit of a(n) is 2, 4, 6 or 8. - Colin Barker, Aug 04 2014
LINKS
EXAMPLE
607 is in the sequence because 607 - 6 = 601, which is prime.
PROG
(PARI) select(p->v=vecsort(digits(p), , 8); isprime(p-v[1+!v[1]]), primes(2000))
(Magma) [p: p in PrimesUpTo(9000) | IsPrime(p-d) where d is [i: i in Set(Intseq(p)) | not IsZero(i)][1]]; // Bruno Berselli, Jul 31 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Jul 31 2014
STATUS
approved