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 A098028 Smallest prime p such that p-2 is a product of exactly n distinct primes. 1
 5, 17, 107, 1367, 15017, 285287, 6561557, 179444267, 3234846617, 100280245067, 3710369067407, 196649560572467, 8309321386330967, 307444891294245707, 24615215445537161447, 961380175077106319537, 78523577350789412776937 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE 1367 is the 4th term in the sequence because it is followed by primes 1997, 2417, 3137, 3257, ... with the property 1367-2 = 3*5*7*13, 1997-2 = 3*5*7*19, 2417-2 = 3*5*7*23, 3137-2 = 3*5*11*19, 3257-2 = 3*5*7*31, ... MATHEMATICA Do[s = 3; While[ ! (Length[FactorInteger[Prime[s] - 2]] == n && Max[Last /@ FactorInteger[Prime[s] - 2]] == 1), s++ ]; Print[Prime[s]], {n, 1, 8}] (* Ryan Propper, Sep 01 2005 *) With[{pn=PrimeNu[Prime[Range[11*10^6]]-2]}, Prime[#]&/@Flatten[Table[ Position[ pn, n, {1}, 1], {n, 8}]]] (* The program takes some time to generate the first 8 terms of the sequence *) (* Harvey P. Dale, Jan 18 2016 *) CROSSREFS Sequence in context: A297476 A235871 A240803 * A100301 A084167 A267143 Adjacent sequences:  A098025 A098026 A098027 * A098029 A098030 A098031 KEYWORD nonn,hard AUTHOR Lekraj Beedassy, Sep 10 2004 EXTENSIONS Extended by Ray Chandler, Sep 18 2004 One more term from Ryan Propper, Sep 01 2005 More terms from Don Reble, Apr 03 2006 STATUS approved

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Last modified August 7 12:01 EDT 2022. Contains 355985 sequences. (Running on oeis4.)