OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
6 = 3*2 and 3 - 2 = 1 (odd nonprime), so 6 is a term;
12 = 3*2*2 and 3 - 2 = 1 (odd nonprime), so 12 is a term;
18 = 3*3*2 and 3 - 2 = 1 (odd nonprime), so 18 is a term;
22 = 11*2 and 11 - 2 = 9 (odd nonprime), so 22 is a term.
MAPLE
MATHEMATICA
lpfQ[n_]:=Module[{fi=Transpose[FactorInteger[n]][[1]], c}, c= Last[fi]-First[fi]; OddQ[c]&&!PrimeQ[c]]; Select[Range[300], lpfQ] (* Harvey P. Dale, Nov 25 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jan 08 2009
EXTENSIONS
Corrected (69 replaced by 68, 203 removed) by R. J. Mathar, May 05 2010
STATUS
approved