

A036337


Largest integer with n digits and exactly n prime factors (counted with multiplicity).


3



7, 95, 994, 9999, 99996, 999992, 9999968, 99999840, 999999968, 9999999900, 99999999840, 999999999744, 9999999998720, 99999999998400, 999999999999000, 9999999999999744, 99999999999995904, 999999999999967232, 9999999999999989760, 99999999999999995904
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OFFSET

1,1


COMMENTS

If all prime factors are distinct then a(n) >= A002110(n) which might give a contradiction for large enough n and so some primes have a multiplicity > k for some nonnegative k.  David A. Corneth, Oct 30 2018


LINKS

Table of n, a(n) for n=1..20.
C. Rivera, Composed primes (a related puzzle).


EXAMPLE

95 = 5 * 19, while 96, 97, 98, 99 and 100 have, respectively, 6,1,3,3 and 4 prime factors; thus 95 is the largest two digit number with exactly two prime factors.


PROG

(PARI) a(n) = forstep(i = 10^n1, 10^(n1), 1, if(bigomega(i) == n, return(i))) \\ David A. Corneth, Oct 30 2018


CROSSREFS

Cf. A002110, A036335, A036336, A036338.
Sequence in context: A015225 A183521 A342109 * A186378 A244856 A201990
Adjacent sequences: A036334 A036335 A036336 * A036338 A036339 A036340


KEYWORD

nonn,base


AUTHOR

Patrick De Geest, Dec 15 1998


EXTENSIONS

More terms and better description from Matthew Conroy, May 25 2001
a(19) and a(20) from Zak Seidov, Oct 30 2018


STATUS

approved



