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A087450 Smallest number (see comment for representation) with all identical digits having n distinct prime divisors. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

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

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}]

CROSSREFS

Cf. A087331.

Sequence in context: A072239 A079350 A070605 * A176650 A046465 A134926

Adjacent sequences:  A087447 A087448 A087449 * A087451 A087452 A087453

KEYWORD

base,nonn

AUTHOR

Robert G. Wilson v, Sep 06 2003

EXTENSIONS

More terms from David Wasserman, Jun 03 2005

STATUS

approved

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Last modified February 23 18:13 EST 2019. Contains 320437 sequences. (Running on oeis4.)