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
KEYWORD
nonn,base
AUTHOR
Colin Barker, Jul 31 2014
STATUS
approved