OFFSET
1,1
EXAMPLE
74 = 2*37, 529 = 23*23.
MATHEMATICA
nn = 150; p = Prime[Range[nn]]; t = {2}; Do[If[p[[n + 1]] - p[[n]] != 2 && p[[n]] - p[[n - 1]] != 2, AppendTo[t, p[[n]]]], {n, 2, nn - 1}]; Select[Range[2, t[[-1]]], ! PrimeQ[#] && Complement[Transpose[FactorInteger[#]][[1]], t] == {} &] (* T. D. Noe, May 21 2013 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Walter Carlini, Jan 18 2005
EXTENSIONS
Corrected and extended by Arkadiusz Wesolowski, May 21 2013
STATUS
approved