Wieferich primes: Difference between revisions
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m (→{{header|REXX}}: simplified program, added/changed whitespace and comments.) |
m (→{{header|REXX}}: changed some comments and whitespace.) |
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!.=0; !.2=1; !.3=1; !.5=1; !.7=1; !.11=1 /* " " " " (semaphores).*/ |
!.=0; !.2=1; !.3=1; !.5=1; !.7=1; !.11=1 /* " " " " (semaphores).*/ |
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#= 5; sq.#= @.# **2 /*number of primes so far; prime². */ |
#= 5; sq.#= @.# **2 /*number of primes so far; prime². */ |
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do j=@.#+2 by 2 to n-1; parse var j '' -1 _ /*find odd primes from here on.*/ |
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if _==5 then iterate /*get right digit; J ÷ by 5? */ |
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if j//3==0 then iterate; if j//7==0 then iterate /*J ÷ by 3? J ÷ by 7? */ |
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if j// 3==0 then iterate /*" " " 3? */ |
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if j// 7==0 then iterate /*" " " 7? */ |
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do k=5 while sq.k<=j /* [↓] divide by the known odd primes.*/ |
do k=5 while sq.k<=j /* [↓] divide by the known odd primes.*/ |
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if j//@.k==0 then iterate j /*Is J ÷ a P? Then not prime. ___ */ |
if j//@.k==0 then iterate j /*Is J ÷ a P? Then not prime. ___ */ |
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