891011

Appears in sequences

• 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.at n=47A090910
• Concatenation of next n imperfect numbers.at n=3A134733
• Triangle read by rows: T(n,k) = value of the string of length k beginning at position n in the concatenation of natural numbers in decimal representation, 1<=k<=n.at n=33A162711
• Numbers whose decimal expansion is a concatenation of 4 consecutive increasing nonnegative numbers.at n=7A279204
• Write down the positive integers. To obtain the terms of the sequence, concatenate groups of these so that the last number of each concatenated group is a prime.at n=4A367431