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 A140775 A number n is included if p + n/p is prime for every prime p that divides n. 3
 2, 6, 10, 22, 30, 34, 42, 58, 70, 78, 82, 102, 118, 130, 142, 190, 202, 210, 214, 274, 298, 310, 322, 330, 358, 382, 394, 442, 454, 462, 478, 510, 538, 562, 582, 610, 622, 658, 694, 714, 730, 742, 790, 838, 862, 922, 930, 970, 1002, 1038, 1042, 1110, 1138, 1198 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms of this sequence are even and squarefree. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE The primes dividing 70 are 2, 5, 7. Now, 2 + 70/2 = 37; 5 + 70/5 = 19; 7 + 70/7 = 17. Since 37, 19 and 17 are each prime, then 70 is included in this sequence. MATHEMATICA fQ[n_] := Block[{p = First@ Transpose@ FactorInteger@ n}, Union@ PrimeQ[p + n/p] == {True}]; Select[ Range[2, 1221], fQ@# &] - Robert G. Wilson v, May 30 2008 pnpQ[n_]:=AllTrue[#+n/#&/@Transpose[FactorInteger[n]][[1]], PrimeQ]; Select[ Range[2, 1200], pnpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 15 2016 *) CROSSREFS Cf. A140776, A140777. Sequence in context: A112861 A180230 A186296 * A077064 A080715 A034168 Adjacent sequences:  A140772 A140773 A140774 * A140776 A140777 A140778 KEYWORD nonn AUTHOR Leroy Quet, May 29 2008 EXTENSIONS More terms from Robert G. Wilson v, May 30 2008 STATUS approved

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Last modified November 30 08:16 EST 2021. Contains 349419 sequences. (Running on oeis4.)