Blum integer: Difference between revisions

=={{header|Ruby}}==

<syntaxhighlight lang="ruby" line>require 'prime'

BLUM_EXP = [1, 1]

blums = (1..).step(2).lazy.select do |c|

next if c % 5 == 0

primes, exps = c.prime_division.transpose

exps == BLUM_EXP && primes.all?{|pr| (pr-3) % 4 == 0}

end

n, m = 50, 26828

res = blums.first(m)

puts "First #{n} Blum numbers:"

res.first(n).each_slice(10){|s| puts "%4d"*s.size % s}

puts "\n#{m}th Blum number: #{res.last}"</syntaxhighlight>

{{out}}

<pre>First 50 Blum numbers:

21 33 57 69 77 93 129 133 141 161

177 201 209 213 217 237 249 253 301 309

321 329 341 381 393 413 417 437 453 469

473 489 497 501 517 537 553 573 581 589

597 633 649 669 681 713 717 721 737 749

26828th Blum number: 524273

</pre>