A339723 Start with a(1)=1. Thereafter, to get a(n), write a(n-1) in binary, write down all its run lengths, and concatenate them in binary, getting k. Then a(n) = k unless k is already in the sequence, in which case a(n) = smallest missing number.

1, 2, 3, 4, 6, 5, 7, 8, 9, 13, 11, 14, 10, 15, 12, 16, 17, 18, 27, 22, 29, 19, 26, 23, 20, 30, 21, 31, 24, 25, 28, 32, 33, 34, 35, 36, 54, 45, 59, 37, 55, 38, 53, 47, 39, 40, 41, 61, 42, 63, 43, 62, 44, 58, 46, 48, 49, 50, 51, 52, 56, 57, 60, 64, 65, 66, 67, 68, 69

Offset: 1

Author

Finnegan R. Manthe, Dec 14 2020

Keywords

• nonn
• base

Examples

			for n=3, a(2) = 2 in binary is 10 with run length 1,1, concatenated is 11 which in base 10 is k=3. So a(3)=3.
For n=7 doing this gives 7 which is already in the sequence (at n=5) so we put 6 as it is the smallest number not already in the sequence.
		

Links

• Finnegan R. Manthe, Generation Code
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A175930 (concatenated run lengths).