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A231433
The digits of a(n) and a(n+1) taken together are the digits of a prime; least permutation of the nonnegative integers with this property.
5
0, 11, 2, 3, 1, 4, 7, 6, 10, 9, 5, 12, 8, 18, 13, 15, 14, 17, 20, 23, 21, 16, 19, 22, 30, 25, 27, 26, 29, 24, 31, 28, 33, 32, 35, 36, 34, 37, 39, 38, 41, 42, 43, 45, 47, 44, 51, 40, 49, 46, 57, 50, 53, 48, 59, 56, 63, 52, 61, 54, 67, 55, 69, 58, 70, 60, 71, 62, 72
OFFSET
0,2
COMMENTS
The offset is zero to have a permutation.
Sequence A128280 is an "arithmetic" analog, where instead of concatenation of digits, the terms are added.
Sequences A228407 and A228410 are the variants where "prime" is replaced by "palindrome".
LINKS
E. Angelini, Two make a prime, Nov 09 2013
EXAMPLE
Start with a(0)=0. The least prime having this digit is 101, so a(1)=11. Since 0 cannot be used any more and 111 is not a prime, the least digit that can be added to get the digits of some prime (namely 211) is a(2)=2, then a(3)=3 yields 23, etc.
See also the link to Angelini's post.
PROG
(PARI) {a=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
Sequence in context: A099268 A070277 A109864 * A240454 A375102 A099756
KEYWORD
nonn,base
AUTHOR
Eric Angelini and M. F. Hasler, Nov 09 2013
STATUS
approved