Brilliant numbers
1 through 7 are fast. 8 and 9 take a bit longer.
use Lingua::EN::Numbers;
# Find an abundance of primes to use to generate brilliants
my %primes = (2..100000).grep( &is-prime ).categorize: { .chars };
# Generate brilliant numbers
my @brilliant = lazy flat (1..*).map: -> $digits {
sort flat (^%primes{$digits}).race.map: { %primes{$digits}[$_] X× (flat %primes{$digits}[$_ .. *]) }
};
# The task
put "First 100 brilliant numbers:\n" ~ @brilliant[^100].batch(10)».fmt("%4d").join("\n") ~ "\n" ;
for 1 .. 7 -> $oom {
my $threshold = exp $oom, 10;
my $key = @brilliant.first: :k, * >= $threshold;
printf "First >= %13s is %9s in the series: %13s\n", comma($threshold), ordinal-digit(1 + $key, :u), comma @brilliant[$key];
}
Output:
First 100 brilliant numbers:
4 6 9 10 14 15 21 25 35 49
121 143 169 187 209 221 247 253 289 299
319 323 341 361 377 391 403 407 437 451
473 481 493 517 527 529 533 551 559 583
589 611 629 649 667 671 689 697 703 713
731 737 767 779 781 793 799 803 817 841
851 869 871 893 899 901 913 923 943 949
961 979 989 1003 1007 1027 1037 1067 1073 1079
1081 1121 1139 1147 1157 1159 1189 1207 1219 1241
1247 1261 1271 1273 1333 1343 1349 1357 1363 1369
First >= 10 is 4ᵗʰ in the series: 10
First >= 100 is 11ᵗʰ in the series: 121
First >= 1,000 is 74ᵗʰ in the series: 1,003
First >= 10,000 is 242ⁿᵈ in the series: 10,201
First >= 100,000 is 2505ᵗʰ in the series: 100,013
First >= 1,000,000 is 10538ᵗʰ in the series: 1,018,081
First >= 10,000,000 is 124364ᵗʰ in the series: 10,000,043
First >= 100,000,000 is 573929ᵗʰ in the series: 100,140,049
First >= 1,000,000,000 is 7407841ˢᵗ in the series: 1,000,000,081
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