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- #!/usr/bin/ruby
- # https://oeis.org/A076960
- # Number of primes <= n!.
- # https://oeis.org/A003604
- # a(n) = A003604(2*n) - A003604(n). - ~~~~
- # 58893601709293849, 23688535118130027712
- # a(10)-a(11) from ~~~~ [based on data from A003604]
- var a = [ 0, 0, 1, 3, 9, 30, 128, 675, 4231, 30969, 258689, 2428956, 25306287, 289620751, 3610490805, 48686912930, 706003798139, 10953617995740, 181035032207760, 3175094503778521, 58893601709552538, 1151825702178908788, 23688535118132456668, 511050155316058710033]
- for i in (0 .. a.len>>1) {
- say ("a(#{i}) = ", a[2*i]-a[i])
- }
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