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A070843
Largest n-digit number with exactly n distinct prime divisors. There are no further terms.
2
9, 99, 996, 9996, 99990, 999570, 9999990, 99981420, 999068070, 9592993410
OFFSET
1,1
COMMENTS
Primes counted without multiplicity. - Harvey P. Dale, Sep 30 2021
EXAMPLE
a(4) = 9996 with the prime divisors 2,3,7 and 17.
MATHEMATICA
Do[k = 10^n - 1; While[Length[FactorInteger[k]] != n, k-- ]; Print[k], {n, 1, 10}] (* Ryan Propper, Nov 05 2005 *)
lnpd[n_]:=Module[{k=10^n-1}, While[PrimeNu[k]!=n, k--]; k]; Array[lnpd, 10] (* Harvey P. Dale, Sep 30 2021 *)
CROSSREFS
Cf. A070842.
Sequence in context: A320075 A101564 A242811 * A261512 A242809 A108908
KEYWORD
base,nonn,fini,full
AUTHOR
Amarnath Murthy, May 12 2002
EXTENSIONS
More terms from Rick L. Shepherd, May 14 2002
a(10) from Ryan Propper, Nov 05 2005
Edited by Ray Chandler, Feb 15 2009
Definition clarified by Harvey P. Dale, Sep 30 2021
STATUS
approved