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A303157
Lexicographically earliest sequence of distinct terms such that the successive quantities of digits between two successive 2s are given by the succession of the sequence's digits itself.
9
0, 1, 2, 20, 21, 3, 23, 4, 22, 5, 6, 24, 25, 7, 8, 26, 9, 27, 10, 28, 11, 12, 13, 29, 32, 14, 15, 42, 16, 17, 18, 200, 201, 19, 203, 204, 30, 52, 31, 33, 34, 62, 35, 36, 37, 38, 205, 206, 39, 40, 207, 41, 43, 44, 72, 45, 208, 46, 47, 82, 92, 209, 210, 48, 49, 50, 202, 120, 211, 212, 51, 121
OFFSET
1,3
COMMENTS
The sequence starts with a(1) = 0 and is always extended with the smallest integer not yet present that doesn't lead to a contradiction. This sequence is a permutation of the numbers >= 0.
LINKS
EXAMPLE
There are:
0 digit between the 2 of "2" and the 2 of "20";
1 digit between the 2 of "20" and the 2 of "21";
2 digits between the 2 of "21" and the 2 of "23";
2 digits between the 2 of "23" and the first 2 of "22";
0 digit between the 2s of "22";
2 digits between the last 2 of "22" and the 2 of "24";
1 digit between the 2 of "24" and the 2 of "25";
3 digits between the 2 of "25" and the 2 of "26";
2 digits between the 2 of "26" and the 2 of "27";
3 digits between the 2 of "27" and the 2 of "28";
4 digits between the 2 of "28" and the 2 of "12";
2 digits between the 2 of "12" and the 2 of "29";
etc.
We see that the first column here is the succession of the digits of the sequence, as well as the size of each chunk of digits between two successive 2s.
CROSSREFS
Cf. A303151 for the same idea with 1s as chunk's separators, A303158 with 3s, A302943 with 4s, A303163 with 5s, A303164 with 6s, A303166 with 7s, A303167 with 8s and A303171 with 9s.
Sequence in context: A075031 A273466 A278938 * A338994 A217394 A072998
KEYWORD
nonn,base
AUTHOR
STATUS
approved