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 A336515 a(1) = 1, and for any n > 0, a(n+1) is the number of k in the range 1..n such that the binary representation of a(k) appears as a substring in the binary representation of a(n). 2
 1, 1, 2, 3, 3, 4, 4, 5, 4, 6, 6, 7, 5, 5, 6, 8, 7, 6, 9, 7, 7, 8, 8, 9, 8, 10, 7, 9, 9, 10, 8, 11, 9, 11, 10, 9, 12, 13, 13, 14, 15, 10, 10, 11, 11, 12, 14, 16, 12, 15, 11, 13, 15, 12, 16, 13, 16, 14, 17, 12, 17, 13, 17, 14, 18, 13, 18, 14, 19, 15, 13, 19, 16 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS This sequence is unbounded. LINKS Rémy Sigrist, Table of n, a(n) for n = 1..10000 Rémy Sigrist, Density plot of the first 100000000 terms Rémy Sigrist, PARI program for A336515 EXAMPLE The first terms, alongside their binary representation and the corresponding k's, are:   n   a(n)  bin(a(n))  k's   --  ----  ---------  -------------    1     1          1  N/A    2     1          1  {1}    3     2         10  {1, 2}    4     3         11  {1, 2, 3}    5     3         11  {1, 2, 4}    6     4        100  {1, 2, 4, 5}    7     4        100  {1, 2, 3, 6}    8     5        101  {1, 2, 3, 6, 7}    9     4        100  {1, 2, 3, 8}   10     6        110  {1, 2, 3, 6, 7, 9} PROG (PARI) See Links section. CROSSREFS Cf. A336514 (decimal variant). Sequence in context: A300118 A256544 A321211 * A130500 A072073 A320757 Adjacent sequences:  A336512 A336513 A336514 * A336516 A336517 A336518 KEYWORD nonn,look,base AUTHOR Rémy Sigrist, Jul 24 2020 STATUS approved

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Last modified June 16 21:55 EDT 2021. Contains 345080 sequences. (Running on oeis4.)