A308540 a(n) is the least nonnegative number whose digits do not appear in order (not necessarily consecutively) in the concatenation of all previous terms.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 22, 33, 44, 55, 66, 77, 88, 99, 100, 332, 554, 776, 998, 1001, 3322, 5544, 7766, 9988, 33220, 33221, 55445, 77667, 99889, 332200, 332211, 776674, 776675, 3322008, 3322009, 7766741, 7766755, 33220088, 33220099, 77667411

Offset

1,3

Comments

This sequence is a variant of A048991.

Links

Table of n, a(n) for n=1..45.

Rémy Sigrist, C program for A308540

Example

The first terms are necessarily the one-digit numbers: a(1) = 0, a(2) = 1, ..., a(10) = 9.
The number 10 does not appear in "0123456789", hence a(11) = 10.
The digits of every number from 11 to 21 appear in order in "012345678910", but this is not the case for the number 22, hence a(12) = 22.

Prog

(C) See Links section.

Crossrefs

See A309340 for the binary variant.

Cf. A048991.

Sequence in context: A276633 A298482 A301801 * A179310 A114806 A239664

Adjacent sequences: A308537 A308538 A308539 * A308541 A308542 A308543

Keyword

nonn,base

Author

Rémy Sigrist, Jul 24 2019

Status

approved