A090910 a(n+1) is the least positive integer k such that (1) k is a one-digit number or the concatenation of two or more consecutive numbers; (2) |k-a(n)| is prime; (3) k is not already in the sequence; and (4) |k-a(n)| is not the absolute difference of two previous consecutive members of the sequence.

1, 3, 6, 23, 4, 9, 2, 45, 8, 67, 56, 123, 34, 5, 78, 7, 234, 1415, 1234, 1011, 910, 89, 456, 1213, 12, 2345, 678, 2425, 3456, 1819, 123456, 2627, 45678, 4445, 101112, 3031, 5678, 345, 1516, 789, 1718, 567, 2728, 100101, 2324, 4567, 1314, 891011, 4344

Offset

0,2

Links

Table of n, a(n) for n=0..48.

Example

12 follows 23 as 23-12 = 11 is prime.

Crossrefs

Cf. A090911, A090912.

Sequence in context: A029848 A366483 A117850 * A256674 A176424 A341549

Adjacent sequences: A090907 A090908 A090909 * A090911 A090912 A090913

Keyword

base,nonn,easy

Author

Amarnath Murthy, Dec 15 2003

Extensions

Edited and extended by David Wasserman, Feb 14 2006

Status

approved