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A180059 Smallest k such that binary weight of k*n is less than binary weight of k, or zero if no such k exists (for n = powers of 2). 1
0, 0, 11, 0, 13, 11, 23, 0, 29, 13, 47, 11, 79, 23, 47, 0, 61, 29, 27, 13, 55, 47, 23, 11, 41, 79, 19, 23, 53, 47, 95, 0, 125, 61, 59, 29, 111, 27, 55, 13, 25, 55, 143, 47, 47, 23, 47, 11, 209, 41, 91, 79, 29, 19, 149, 23, 575, 53, 139, 47, 277, 95, 191, 0, 253, 125, 107, 61 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
A000120(n) > A000120(k*n).
MATHEMATICA
s={}; Do[Do[If[Count[IntegerDigits[k x, 2], 1]<Count[IntegerDigits[x, 2], 1],
AppendTo[s, {k, x}]; Break[]], {x, 10000}], {k, 2, 200}]; s (* Zak Seidov, Oct 24 2013 *)
PROG
(PARI) a(n)=if((n<=1)||((n>>valuation(n, 2))==1), 0, my(k=3); while(hammingweight(k*n)>=hammingweight(k), k+=2); k ) \\ Charles R Greathouse IV, Oct 19 2013
CROSSREFS
Sequence in context: A088623 A167166 A271572 * A147765 A087556 A082268
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Aug 08 2010
STATUS
approved

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Last modified July 18 16:59 EDT 2024. Contains 374388 sequences. (Running on oeis4.)