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.
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.
Terms
- a(0) =1a(1) =3a(2) =6a(3) =23a(4) =4a(5) =9a(6) =2a(7) =45a(8) =8a(9) =67a(10) =56a(11) =123a(12) =34a(13) =5a(14) =78a(15) =7a(16) =234a(17) =1415a(18) =1234a(19) =1011a(20) =910a(21) =89a(22) =456a(23) =1213a(24) =12a(25) =2345a(26) =678a(27) =2425a(28) =3456a(29) =1819
External references
- oeis: A090910