A300889 - OEIS

%I #8 Mar 15 2018 06:19:00

%S 1,2,9,4,5,18,21,8,9,10,33,36,65,42,165,16,17,18,133,20,21,66,69,72,

%T 325,130,81,84,145,330,341,32,33,34,1365,36,37,266,273,40,41,42,129,

%U 132,585,138,329,144,1029,650,1173,260,265,162,165,168,513,290,649

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

%H Rémy Sigrist, <a href="/A300889/b300889.txt">Table of n, a(n) for n = 1..10000</a>

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

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

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

%e The first terms, alongside their binary representation, are:

%e   n  a(n)    binary(a(n))

%e   -- ----    ------------

%e    1    1           1

%e    2    2          10

%e    3    9        1001

%e    4    4         100

%e    5    5         101

%e    6   18       10010

%e    7   21       10101

%e    8    8        1000

%e    9    9        1001

%e   10   10        1010

%e   11   33      100001

%e   12   36      100100

%e   13   65     1000001

%e   14   42      101010

%e   15  165    10100101

%e   16   16       10000

%e   17   17       10001

%e   18   18       10010

%e   19  133    10000101

%e   20   20       10100

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

%Y Cf. A003714, A300867.

%K nonn,base

%O 1,2

%A _Rémy Sigrist_, Mar 14 2018