OFFSET
1,2
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..10000
M. F. Hasler, in reply to E. Angelini, Two make a prime, SeqFan list, Nov 09 2013
EXAMPLE
Start with a(1)=1. The same number cannot be used twice, so the least prime that can be made with this digit is 13, so a(2)=3.
PROG
(PARI) {a=1; u=0; for(n=1, 99, u+=1<<a; print1(a", "); for(k=1, 9e9, bittest(u, k)&&next; d=Vec(Str(a, k)); for(p=0, (#d)!-1, isprime(eval(concat(t=vecextract(d, numtoperm(#d, p)))))&&t[1]>"0"&&(a=k)&&next(3))))}
CROSSREFS
KEYWORD
nonn,base
AUTHOR
M. F. Hasler, Nov 09 2013
STATUS
approved