OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
96=2*2*2*2*2*3 (6-almost prime) and 2+2+2+2+2+3=13 is a prime.
MATHEMATICA
Select[Range[8000], Last[Plus@@FactorInteger[ # ]]==6&&PrimeQ[Plus@@Times@@ Transpose[FactorInteger[ # ]]]&]
sfp6Q[n_]:=Module[{pf=Flatten[Table[#[[1]], #[[2]]]&/@FactorInteger[n]]}, Length[ pf]==6&&PrimeQ[Total[pf]]]; Select[Range[4400], sfp6Q] (* Harvey P. Dale, Jul 01 2018 *)
PROG
(PARI) is(n)=my(f=factor(n)); sum(i=1, #f~, f[i, 2])==6 && isprime(sum(i=1, #f~, f[i, 1]*f[i, 2])) \\ Charles R Greathouse IV, Oct 11 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jun 12 2005
STATUS
approved