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 A154365 Numbers n such that the smallest prime factor of composite(n) + the largest prime factor of composite(n) is prime and the sum of prime factors (with multiplicity) of composite(n) is prime. 1
 2, 5, 6, 13, 22, 27, 32, 37, 41, 57, 59, 64, 65, 71, 79, 87, 103, 107, 135, 152, 155, 166, 196, 215, 235, 237, 253, 261, 286, 287, 306, 307, 316, 348, 366, 372, 373, 386, 393, 404, 423, 438, 448, 459, 490, 507, 524, 539, 568, 577, 586, 591, 632, 653, 668, 669 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 MATHEMATICA lpfQ[{n_, c_}]:=Module[{f=FactorInteger[c]}, PrimeQ[f[[1, 1]]+f[[-1, 1]]] && PrimeQ[Total[Flatten[Table[#[[1]], #[[2]]]&/@f]]]]; Module[{cmps=Select[ Range[1000], CompositeQ], len}, len=Length[cmps]; Select[Thread[ {Range[ len], cmps}], lpfQ]][[All, 1]] (* Harvey P. Dale, Aug 16 2020 *) CROSSREFS Sequence in context: A038191 A321472 A087128 * A247959 A243799 A029544 Adjacent sequences:  A154362 A154363 A154364 * A154366 A154367 A154368 KEYWORD nonn,less AUTHOR Juri-Stepan Gerasimov, Jan 08 2009 EXTENSIONS Edited and extended by Charles R Greathouse IV, Mar 31 2010 STATUS approved

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Last modified May 15 18:26 EDT 2021. Contains 343920 sequences. (Running on oeis4.)