OFFSET
1,1
COMMENTS
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
34=2*17 (semiprime), with 3+4=7 and 2+17=19 both prime.
MATHEMATICA
psddQ[n_]:=!IntegerQ[Sqrt[n]]&&PrimeOmega[n]==2&&PrimeQ[Total[ IntegerDigits[n]]] && PrimeQ[Total[Transpose[FactorInteger[n]][[1]]]]; Select[Range[5500], psddQ] (* Harvey P. Dale, Oct 03 2012 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Jun 12 2005
STATUS
approved