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A030173
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Differences p(i)-p(j) between primes, sorted in numerical order.
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11
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1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20, 21, 22, 24, 26, 27, 28, 29, 30, 32, 34, 35, 36, 38, 39, 40, 41, 42, 44, 45, 46, 48, 50, 51, 52, 54, 56, 57, 58, 59, 60, 62, 64, 65, 66, 68, 69, 70, 71, 72, 74, 76, 77, 78, 80, 81, 82, 84, 86, 87, 88, 90
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OFFSET
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1,2
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COMMENTS
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Conjectured (Polignac 1849) to be union of even numbers and the odd primes minus 2.
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LINKS
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MATHEMATICA
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nn = 90; Union[Range[2, nn, 2], Prime[Range[2, PrimePi[nn+2]]] - 2]
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PROG
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(PARI) print1(1); p=3; forprime(q=5, 1e3, forstep(n=p-1, q-3, 2, print1(", "n)); print1(", ", q-2); p=q) \\ conjectural; Charles R Greathouse IV, Jul 02 2011
(PARI) isOK(n)=if(n%2, isprime(n+2), forprime(p=3, , isprime(n+p)&&return(1)));
for(n=1, 10^100, isOK(n)&print1(n, ", ")) \\ unconditionally outputs correct values only, will "hang" forever if conjecture is false once that exceptional even number is reached; Jeppe Stig Nielsen, Sep 23 2015
(Haskell)
import Data.List.Ordered (union)
a030173 n = a030173_list !! (n-1)
a030173_list = union [2, 4 ..] $ tail a040976_list
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CROSSREFS
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KEYWORD
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nonn,easy,nice
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AUTHOR
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Alexander Grasser [Graesser] (alex(AT)computicket.com)
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STATUS
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approved
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