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

1,2

Comments

Conjecture: the sequence is defined for all n.

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

Links

Table of n, a(n) for n=1..10.

Formula

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

Example

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.

Sequence in context: A242621 A206385 A263052 * A302452 A113105 A132567

Adjacent sequences: A090332 A090333 A090334 * A090336 A090337 A090338

Keyword

nonn,base,more

Author

Reinhard Zumkeller, Nov 26 2003

Extensions

More terms from David Wasserman, Dec 13 2005

Status

approved