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Search: id:A097526
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| A097526 |
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Least k such that k*P(n)#-P(n+2) and k*P(n)#+P(n+2) are both primes with P(i)=i-th prime and P(i)#=i-th primorial. |
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+0
1
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| 4, 2, 1, 1, 2, 5, 2, 7, 8, 5, 13, 36, 3, 55, 8, 5, 186, 22, 17, 45, 69, 16, 57, 1, 34, 99, 367, 15, 39, 321, 459, 17, 17, 51, 215, 608, 108, 431, 439, 346, 405, 789, 413, 268, 1744, 70, 889, 33, 42, 1883, 2489, 76, 3246, 1219, 849, 214, 870, 208, 197, 619, 323, 3418, 39
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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2*3-7=-1
2*2*3-7=5 prime 2*2*3+7=19 prime so for n=2 k=2
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MATHEMATICA
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Primorial[n_] := Product[ Prime[i], {i, n}]; f[n_] := Block[{k = 1, p = Primorial[n], q = Prime[n + 2]}, While[k*p - q < 2 || !PrimeQ[k*p - q] || !PrimeQ[k*p + q], k++ ]; k]; Table[ f[n], {n, 63}] (from Robert G. Wilson v Aug 31 2004)
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CROSSREFS
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Sequence in context: A068930 A144260 A036466 this_sequence A051149 A152145 A051758
Adjacent sequences: A097523 A097524 A097525 this_sequence A097527 A097528 A097529
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KEYWORD
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easy,nonn
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AUTHOR
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Pierre CAMI (pierrecami(AT)tele2.fr), Aug 27 2004
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 31 2004
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