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 A300889 a(n) is the least positive multiple of n which is a Fibbinary number (A003714). 2

%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

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Last modified June 8 04:57 EDT 2023. Contains 363157 sequences. (Running on oeis4.)