⍝ Prime numbers: pco ⎕io ⍝ the first prime 2 pco 2 5⍴ ⍳10 ⍝ the first 10 primes in a 2 by 5 table 2 3 5 7 11 13 17 19 23 29 pco 1234567 ⍝ the 1234567-th prime 19394489 ¯1 pco 19394509 ⍝ the number of primes < 19394509 1234567 ¯1 pco 97 ⍝ # primes < 97 24 ¯1 pco 97.5 ⍝ # primes < 97.5 25 pco 24 ⍝ the 24-th prime 89 ¯1 pco ¯1+2*31 ⍝ # primes < ¯1+2*31 105097564 pco 105097565 ⍝ the 105097565-th prime (counting from 1) 2147483647 1 pco 314159 ⍝ is 314159 a prime? 1 1 pco 113*2 ⍝ [AA] 0 {⍵/⍳⍴⍵} 1 pco ⍳25 ⍝ all the primes less than 25 2 3 5 7 11 13 17 19 23 0 pco 144 17 49 ⍝ which numbers are not prime? 1 0 1 3 pco 144 ⍝ prime factorization 2 2 2 2 3 3 2 pco 144 ⍝ primes and exponents 2 3 4 2 ⍬ ≡ 3 pco 1 ⍝ the prime factorization of 1 is null 1 4 pco 10*1 2 3 4 ⍝ the next prime > 10 100 ... 11 101 1009 10007 ¯4 pco 10*1 2 3 4 ⍝ the next prime < 10 100 ... 7 97 997 9973 b←10 pco 10 20 ⍝ primes between 10 and 20. b/10 to 19 ⍝ prime between 10 and 20. 11 13 17 19 ⍝ Errors: pco 105097565+1 ⍝ too big 11::nonce error pco ¯2 ⍝ too negative 11::assertion failure pco 1,⊂2 3 ⍝ too deep 11::assertion failure pco 3.4 ⍝ unnatural number 11::assertion failure 4 pco 3*31 ⍝ too big 11::nonce error ¯4 pco 2 ⍝ too small 11::assertion failure 3 pco 66 77 ⍝ too many items 11::assertion failure Back to: code Back to: Workspaces