A143073 Least number k such that the binary expansion of n*k has fewer ones than n, or 0 if no such k exists.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 0, 27, 0, 0, 3, 3, 0, 41, 5, 3, 0, 5, 0, 0, 0, 0, 0, 0, 0, 7085, 27, 7, 0, 25, 0, 3, 3, 0, 3, 3, 0, 0, 41, 0, 5, 5, 3, 3, 0, 9, 5, 3, 0, 5, 0, 0, 0, 0, 0, 128207979, 0, 0, 0, 119, 0, 0, 7085, 0, 27, 5, 7, 7, 0, 1657009, 25, 395, 0, 0, 3, 3, 3, 0, 0

Offset: 1

Author

T. D. Noe, Jul 22 2008

Keywords

• nonn

Comments

a(n)=0 indicates that n is a sturdy number (A125121); that is, no multiple of n has fewer ones than the binary expansion of n. If a(n)>0, n is a flimsy number (A005360). Compare with A143069.

Links

• T. D. Noe, Table of n, a(n) for n=1..1000