A275659 The nonprime digits in the sequence appear in blocks and the successive sizes of these blocks are given by the sequence itself.

1, 2, 3, 4, 6, 5, 7, 8, 9, 12, 10, 11, 20, 14, 16, 13, 18, 19, 15, 21, 40, 41, 44, 22, 23, 24, 46, 48, 49, 17, 25, 26, 60, 61, 64, 66, 27, 28, 68, 69, 80, 81, 84, 42, 29, 86, 88, 89, 90, 43, 30, 91, 94, 96, 98, 99, 31, 100, 101, 104, 106, 108, 109, 45, 32, 33, 34, 110, 111, 114, 116, 47, 35, 36, 118, 119, 140, 141, 144, 37, 38, 146

Offset

1,2

Comments

The sequence is started with a(1)=1 and always extended with the smallest integer not yet present that does not lead to a contradiction.

Links

Eric Angelini, Table of n, a(n) for n = 1..1001

Example

The blocks of nonprime digits are indicated hereunder by parentheses; the successive block-sizes are 1, 2, 3, 4, 6, 5, ... which reproduces the sequence itself: (1),2,3,(4,6),5,7,(8,9,1)2,(10,11),2(0,14,16,1)3,(18,19,1)5,...

Crossrefs

Sequence in context: A073284 A057511 A121730 * A244321 A364824 A062894

Adjacent sequences: A275656 A275657 A275658 * A275660 A275661 A275662

Keyword

nonn,base

Author

Eric Angelini and Lars Blomberg, Aug 04 2016

Status

approved