7 lines
405 B
Text
7 lines
405 B
Text
IsPrime ← =⊣⊸°/×
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# Successors (<len) of n where n + S(n) is prime.
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Nexts ← memo(⊂□[]≡◇(□≡⊣)↘1⊕□⊸≡⊢▽⊸≡(IsPrime/+)⧅≠ 2+1⇡)
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# For each partial soln: add valid Nexts, exclude dupes.
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Step ← /◇⊂≡(□▽⊸≡(=∩⧻⊸◴)≡⊂¤⟜(°□˜⊡Nexts⊃⋅∘∘⊣))
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Matches ← ▽=⟜(⊸≡⊣⍥Step-1⊸⊙[[1]])
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&p≡(⧻&p⊸⊢Matches)+1⇡14
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