A300889 a(n) is the least positive multiple of n which is a Fibbinary number (A003714).

1, 2, 9, 4, 5, 18, 21, 8, 9, 10, 33, 36, 65, 42, 165, 16, 17, 18, 133, 20, 21, 66, 69, 72, 325, 130, 81, 84, 145, 330, 341, 32, 33, 34, 1365, 36, 37, 266, 273, 40, 41, 42, 129, 132, 585, 138, 329, 144, 1029, 650, 1173, 260, 265, 162, 165, 168, 513, 290, 649

Offset

1,2

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Formula

a(n) = n * A300867(n).

a(2*n) = 2*a(n).

a(n) = n iff n belongs to A003714.

Example

The first terms, alongside their binary representation, are:
  n  a(n)    binary(a(n))
  -- ----    ------------
   1    1           1
   2    2          10
   3    9        1001
   4    4         100
   5    5         101
   6   18       10010
   7   21       10101
   8    8        1000
   9    9        1001
  10   10        1010
  11   33      100001
  12   36      100100
  13   65     1000001
  14   42      101010
  15  165    10100101
  16   16       10000
  17   17       10001
  18   18       10010
  19  133    10000101
  20   20       10100

Prog

(PARI) a(n) = forstep (k=1, oo, 2, if (bitand(k*n, 2*k*n)==0, return (k*n)))

Crossrefs

Cf. A003714, A300867.

Sequence in context: A281384 A332091 A203648 * A275807 A202324 A199267

Adjacent sequences: A300886 A300887 A300888 * A300890 A300891 A300892

Keyword

nonn,base

Author

Rémy Sigrist, Mar 14 2018

Status

approved