A113760 a(n) is the least number having sum of digits n in base 10 and also exactly n distinct prime factors.

20, 30, 2002, 100130, 30030, 11030110, 1010011310, 21020110020, 10030101101020, 3003001000200110, 1010211202010010, 10020011010010010210110

Offset

2,1

Links

Table of n, a(n) for n=2..13.

Example

a(2)=20 since 2+0=2 and 20=2^2*5 has 2 distinct prime factors.
a(5)=100130 since 1+0+0+1+3+0=5 and 100130=2*5*17*19*31 has 5 distinct prime factors.

Mathematica

Lk[n_] := Block[{k = 2}, While[n != Plus @@ IntegerDigits[k] || n != Length@FactorInteger@k, k++ ]; k]; L = {}; Do[v = Lk[n]; Print[{n, v}]; AppendTo[L, v], {n, 2, 5}]; L

Crossrefs

Sequence in context: A181639 A166631 A167360 * A053679 A158844 A077340

Adjacent sequences: A113757 A113758 A113759 * A113761 A113762 A113763

Keyword

base,hard,more,nonn

Author

Giovanni Resta, Jan 18 2006

Extensions

More terms from Don Reble, Oct 26 2006

Status

approved