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A176877 Numbers that are the product of 3 distinct primes a,b and c, such that a+b+c are prime numbers. 5
165, 273, 345, 385, 399, 435, 561, 595, 651, 665, 715, 759, 777, 795, 885, 903, 957, 1001, 1015, 1065, 1085, 1173, 1209, 1235, 1281, 1335, 1435, 1443, 1463, 1495, 1515, 1533, 1547, 1551, 1615, 1645, 1659, 1677, 1705, 1749, 1767, 1771, 1885, 1947, 1965 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

165=3*5*11; 3+5+11=19,...

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

l[n_]:=Last/@FactorInteger[n]; f[n_]:=First/@FactorInteger[n]; lst={}; Do[If[l[n]=={1, 1, 1}, a=f[n][[1]]; b=f[n][[2]]; c=f[n][[3]]; If[PrimeQ[a+b+c], AppendTo[lst, n]]], {n, 7!}]; lst

With[{upto=2000}, Select[Times@@@Select[Subsets[Prime[Range[ PrimePi[ upto/6]]], {3}], PrimeQ[Total[#]]&]//Union, #<=upto&]] (* Harvey P. Dale, May 15 2017 *)

CROSSREFS

Cf. A006881, A014574, A176875, A176876

Sequence in context: A270175 A319328 A301970 * A323379 A215967 A029563

Adjacent sequences:  A176874 A176875 A176876 * A176878 A176879 A176880

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 27 2010

STATUS

approved

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Last modified December 2 05:01 EST 2021. Contains 349437 sequences. (Running on oeis4.)