The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60, we have over 367,000 sequences, and we’ve crossed 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A316749 A self-"read and extend" sequence built following the rules given in the Comments section. 6
 1, 2, 4, 8, 16, 15, 30, 29, 58, 57, 56, 112, 224, 223, 446, 445, 890, 889, 1778, 1777, 3, 6, 5, 7, 14, 13, 9, 18, 36, 10, 20, 19, 11, 22, 44, 88, 87, 174, 12, 24, 23, 46, 17, 34, 33, 66, 21, 25, 24, 48, 47, 94, 93, 186, 185, 370, 740, 739, 1478, 1477, 2954, 2953, 2952, 5904, 5903, 11806, 23612, 23611, 26, 52 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Start with a(1) = 1 and a(2) = 2; read the sequence digit by digit starting from the left: when the read digit is smaller than the next one, multiply by 2 the last integer of the sequence and extend it with the result; when the read digit is bigger than the next one, subtract 1 from the last integer of the sequence and extend it with the result; when both digits are equal, extend the sequence with the smallest integer not present so far. LINKS Jean-Marc Falcoz, Table of n, a(n) for n = 1..10002 EXAMPLE As the only digit of a(1) = 1 is smaller than 2 (the next digit), we extend the sequence with 4 (that is, 2 times 2); as the only digit of a(2) = 2 is smaller than 4 (the next digit), we extend the sequence with 8 (that is, 2 times 4); as the only digit of a(3) = 4 is smaller than 8 (the next digit), we extend the sequence with 16 (that is, 2 times 8); as the only digit of a(4) = 8 is bigger than 1 (the next digit), we extend the sequence with 15 (that is, 16 minus 1); as the first digit of a(5) = 1 is smaller than 6 (the next digit), we extend the sequence with 30 (that is, 2 times 15); as the last digit of a(5) = 6 is bigger than 1 (the next digit), we extend the sequence with 29 (that is, 30 minus 1); ... as the first digit of a(12) = 1 is equal to 1 (the next digit), we extend the sequence with 3 (this is the smallest integer not yet present in the sequence and is written after a(23) = 1777); etc. CROSSREFS Sequence in context: A301807 A062116 A362896 * A008381 A083780 A309529 Adjacent sequences: A316746 A316747 A316748 * A316750 A316751 A316752 KEYWORD base,nonn,look AUTHOR Eric Angelini and Jean-Marc Falcoz, Jul 12 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 2 09:50 EST 2023. Contains 367517 sequences. (Running on oeis4.)