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A231433
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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.
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5
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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
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OFFSET
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0,2
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COMMENTS
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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".
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LINKS
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EXAMPLE
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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.
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PROG
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(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))))}
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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