A087450 Smallest number (see comment for representation) with all identical digits having n distinct prime divisors.

11, 12, 16, 26, 46, 61, 62, 121, 122, 182, 241, 242, 322, 301, 302, 422, 642, 646, 722, 1006, 601, 602, 842, 962, 1261, 1262, 1201, 1202, 2042, 1681, 1682, 1922, 1801, 1802, 2102, 2402, 2522, 3302, 3361, 3362, 3001, 3002

Offset: 1

Author

Robert G. Wilson v, Sep 06 2003

Keywords

• base
• nonn

Comments

Sequence represented by citing the number of repeated digits concatenated with that digit, i.e. a(8) = 122.

No more terms < 3600. - David Wasserman, Jun 03 2005

Examples

			a(6) = 86 because 66666666= 2*3*11*73*101*137, is 8 digits long and has 6 distinct prime divisors.
		

Crossrefs

Cf. A087331.

Programs

Mathematica

PrimeFactors[n_Integer] := Flatten[Table[ #[[1]], {1}] & /@ FactorInteger[n]]; Do[k = 1; While[t = Table[j*(10^k - 1)/9, {j, 1, 9}]; l = Map[Length, Map[PrimeFactors, t]]; Position[l, n] == {}, k++ ]; d = t[[Position[l, n][[1, 1]]]]; Print[10k + Position[l, n][[1, 1]]], {n, 0, 17}]

Extensions

More terms from David Wasserman, Jun 03 2005