Sequence: smallest number with exactly n divisors

Sequence: smallest number with exactly n divisors is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Calculate the sequence where each term a_n is the smallest natural number that has exactly n divisors.

Task

Show here, on this page, at least the first 15 terms of the sequence.

See also

• OEIS:A005179

Related tasks

• Sequence: smallest number greater than previous term with exactly n divisors
• Sequence: nth number with exactly n divisors‎‎

Perl

Library: ntheory

<lang perl>use strict; use warnings; use ntheory 'divisors';

print "First 15 terms of OEIS: A005179\n"; for my $n (1..15) {

   my $l = 0;
   while (++$l) {
       print "$l " and last if $n == divisors($l);
   }

}</lang>

Output:

First 15 terms of OEIS: A005179
1 2 4 6 16 12 64 24 36 48 1024 60 4096 192 144

Perl 6

Works with: Rakudo version 2019.03

<lang perl6>sub div-count (\x) {

   return 2 if x.is-prime;
   +flat (1 .. x.sqrt.floor).map: -> \d {
       unless x % d { my \y = x div d; y == d ?? y !! (y, d) }
   }

}

my $limit = 15;

put "First $limit terms of OEIS:A005179"; put (1..$limit).map: -> $n { first { $n == .&div-count }, 1..Inf };

</lang>

Output:

First 15 terms of OEIS:A005179
1 2 4 6 16 12 64 24 36 48 1024 60 4096 192 144