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A303166
Lexicographically earliest sequence of distinct terms such that the successive quantities of digits between two successive 7's are given by the succession of the sequence's digits itself.
9
0, 1, 2, 3, 4, 5, 6, 7, 70, 71, 8, 72, 9, 17, 10, 11, 73, 12, 13, 74, 14, 15, 27, 16, 18, 19, 37, 20, 21, 22, 47, 75, 23, 24, 25, 76, 78, 26, 28, 29, 57, 30, 31, 32, 67, 33, 79, 34, 35, 36, 38, 707, 39, 40, 41, 87, 97, 717, 170, 42, 43, 44, 700, 171, 701, 727, 45, 172, 46, 48, 49, 702, 50, 737, 51
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 7 of "7" and the 7 of "70";
1 digit between the 7 of "70" and the 7 of "71";
2 digits between the 7 of "71" and the 7 of "72";
3 digits between the 7 of "72" and the 7 of "17";
4 digits between the 7 of "17" and the 7 of "73";
5 digits between the 7 of "73" and the 7 of "74";
6 digits between the 7 of "74" and the 7 of "27";
7 digits between the 7 of "27" and the 7 of "37";
7 digits between the 7 of "37" and the 7 of "47";
0 digit between the 7 of "47" and the 7 of "75";
7 digits between the 7 of "75" and the 7 of "76";
1 digit between the 7 of "76" and the 7 of "78";
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 7's.
CROSSREFS
Cf. A303151 for the same idea with 1's as chunk's separators, A303157 with 2's, A303158 with 3's, A302943 with 4's, A303163 with 5's, A303164 with 6's, A303167 with 8's and A303171 with 9's.
Sequence in context: A370776 A273475 A278942 * A024649 A037335 A028429
KEYWORD
nonn,base
AUTHOR
STATUS
approved