OFFSET
1,1
COMMENTS
Or, binary weight of 5n is less than binary weight of n.
Also called the 5-flimsy numbers; see the Stolarsky reference.
If m is here, 2m is too. Hence the "primitive solutions" are all odd ones:
13,29,53,55,61,77,103,109,111,117,119,125,157,205,207,213,215,219,221,223,231.
LINKS
Kenneth B. Stolarsky, Integers whose multiples have anomalous digital frequencies, Acta Arithmetica 38 (2) (1980), 117-128.
MATHEMATICA
Select[Range[1000], Count[IntegerDigits[5#, 2], 1]<Count[IntegerDigits[ #, 2], 1]&]
PROG
(PARI) for(k=1, 370, if(hammingweight(5*k) < hammingweight(k), print1(k, ", "))) \\ Hugo Pfoertner, Dec 27 2019
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Aug 08 2010
STATUS
approved