OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
42 = 2*3*7 and 2+3+7-1 is prime, so 42 is a term.
418 = 2*11*19 and 2+11+19-1 is prime, so 418 is a term.
MATHEMATICA
With[{nnn=80}, Take[Times@@@Select[Subsets[Prime[Range[nnn]], {3}], PrimeQ[Total[#] - 1] &]//Union, nnn]]
PROG
(PARI) list(lim)=my(v=List()); forprime(p=5, lim\6, forprime(q=3, min(lim\2\p, p-2), if(isprime(p+q+1), listput(v, 2*p*q)))); Set(v) \\ Charles R Greathouse IV, Aug 23 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Aug 23 2017
STATUS
approved