A302095 a(n) is the smallest positive integer not yet in the increasing sequence that is obtained when the largest digit from a(n-1) is deleted and the remaining digits are permuted such that no digit in a(n) has the same position it had in a(n-1) (counting from left to right). No repeated digits allowed; a(1)=10.

10, 230, 402, 520, 602, 720, 802, 920, 1023, 2104, 3012, 4120, 5012, 6120, 7012, 8120, 9012, 12034, 20153, 31024, 50132, 61023, 70132, 81023, 90132, 120435, 201346, 310254, 401326, 510234, 601342, 710234, 801342, 910234, 1023456, 2104375, 3012456, 4103275, 5012346, 7103254

Offset: 1

Author

Enrique Navarrete, May 19 2018

Keywords

• nonn
• base
• fini
• full

Comments

All terms in the sequence contain 0.

The fact that all digits in the terms are distinct makes the sequence finite.

In fact, the sequence contains 59 terms and a(59)=901325476.

The terms that require the smallest number of permutations to recover their natural ordering are a(1)=10, a(9)=1023 and a(35)=1023456 (one permutation required).

Examples

			a(2)=230 since it is the smallest positive integer not yet in the sequence that is obtained when the largest digit 1 from a(1)=10 is deleted, the remaining digit 0 is permuted from the second to third place, and no digits are repeated.
		

Links

• Enrique Navarrete, Table of n, a(n) for n = 1..59

Crossrefs

Cf. A107353, A297418.