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Search: id:A139440
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| A139440 |
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Numbers n such that primorial(n)/2 - 4 is prime. |
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+0
24
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| 3, 4, 5, 7, 12, 15, 26, 31, 50, 71, 186, 273, 366
(list; graph; listen)
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OFFSET
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1,1
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MATHEMATICA
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k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 4], Print[n]; AppendTo[a, n]], {n, 2, 366}]; a (*Artur Jasinski*)
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CROSSREFS
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Cf. A067026, A067027, A139439, A139440, A139441, A139442, A139443, A139444, A139445, A139446, A139447, A139448, A139449, A139450, A139451, A139452, A139453, A139454, A139455, A139456, A139457, A103514.
Sequence in context: A032890 A092859 A120424 this_sequence A102607 A079463 A101759
Adjacent sequences: A139437 A139438 A139439 this_sequence A139441 A139442 A139443
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KEYWORD
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nonn
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AUTHOR
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Artur Jasinski (grafix(AT)csl.pl), Apr 21 2008
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