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 A125132 Self-describing sequence: sequence starts with a(1) = 1 and a(n) is chosen to be the smallest positive number not already in the sequence such that the assertion "sequence gives the positions of the odd digits when the sequence is read as a string of digits" is true. 5
 1, 3, 5, 2, 7, 8, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 110, 10, 12, 14, 16, 111, 28, 30, 32, 34, 36, 48, 50, 52 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Inspired by Angelini's sequence A114308. LINKS Jean-Marc Falcoz, Table of n, a(n) for n = 1..2001 EXAMPLE Here are the digits strung together (the odd digits occur at positions that are indexed by terms of the sequence): -135278911 1315171921 2325272931 3335373941... Explanation: a(2)=2? No. a(2)=3? Yes, but then the third term has to be odd and 2 has to appear later. a(3)=2? No, a(3) must be odd, so 5. a(4)? Now we can fill in the 2 that has been waiting. And so on. CROSSREFS Cf. A125133 (missing numbers), A114308 (same except need a(n) > a(n-1)). Sequence in context: A210042 A274421 A079313 * A243352 A026184 A026208 Adjacent sequences:  A125129 A125130 A125131 * A125133 A125134 A125135 KEYWORD base,easy,nonn AUTHOR N. J. A. Sloane, Jan 12 2007 EXTENSIONS Corrected and extended by D. S. McNeil, Oct 22 2011 STATUS approved

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Last modified June 5 09:46 EDT 2020. Contains 334829 sequences. (Running on oeis4.)