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.

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

Author

Eric Angelini and M. F. Hasler, Nov 09 2013

Keywords

• nonn
• base

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".

Examples

			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.
		

Links

• Lars Blomberg, Table of n, a(n) for n = 0..9999
• E. Angelini, Two make a prime, Nov 09 2013

Programs

PARI

{a=u=0;for(n=1,99,u+=1<"0"&&(a=k)&&next(3))))}