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A177088 Numbers n such that n^5-n^3-2*n^2+1 is semiprime. 2
5, 7, 9, 11, 13, 14, 17, 19, 20, 26, 27, 29, 31, 34, 40, 41, 42, 43, 49, 50, 51, 53, 54, 56, 61, 62, 63, 64, 66, 68, 71, 72, 74, 76, 88, 89, 92, 95, 97, 105, 107, 108, 109, 110, 113, 115, 116, 117, 119, 125, 127, 128, 130, 133, 134, 135, 136, 138, 139, 142, 144, 145 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[300], PrimeOmega[#^5 - #^3 - 2 #^2 + 1]==2&] (* Vincenzo Librandi, May 14 2014 *)
PROG
(Magma) IsSemiprime:=func<i | &+[d[2]: d in Factorization(i)] eq 2>; [n: n in [2..200] | IsSemiprime(s) where s is n^5-n^3-2*n^2+1]; // Vincenzo Librandi, May 14 2014
CROSSREFS
Sequence in context: A279244 A325797 A128163 * A362486 A168146 A343064
KEYWORD
nonn,easy,less
AUTHOR
Vincenzo Librandi, Jun 05 2010
STATUS
approved

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Last modified July 18 21:02 EDT 2024. Contains 374388 sequences. (Running on oeis4.)