A090335 Smallest number with exactly n distinct prime factors such that in binary representation the divisors >1 form a prefix code.

1, 2, 33, 2093, 239723, 29918977, 17597346187, 17155385292853, 10633323942990239, 15790705299133143889

Offset: 1

Author

Reinhard Zumkeller, Nov 26 2003

Keywords

• nonn
• base
• more

Comments

Conjecture: the sequence is defined for all n.

a(10) <= 281594003343201014885689. - David Wasserman, Dec 13 2005

Examples

			a(3) = 2093 = 7*13*23 with divisors >1: 7, 13, 23, 91, 161, 299 and 2093, which are prefix-free in binary: 111, 1101, 10111, 1011011, 10100001, 100101011 and 100000101101.
		

Crossrefs

Cf. A088862, A090332.

Formula

a(n) = Min{k: A090330(k)=0 and A001221(k)=n}.

Extensions

More terms from David Wasserman, Dec 13 2005