OFFSET

1,1

EXAMPLE

621 is a term: it is the smallest of three consecutive odd composite numbers (621 = 3^3*23, 623 = 7*89, 625 = 5^4) and is also the sum of three consecutive odd composite numbers (205 = 5*41, 207 = 3^2*23, 209 = 11*19, and 205 + 207 + 209 = 621).

MATHEMATICA

fQ[n_]:=!PrimeQ[n]&&!PrimeQ[n+2]&&!PrimeQ[n+4];

lst1=Select[Range[3, 9000, 2], fQ];

lst2=3*Select[Range[3, 3000, 2], fQ]+6;

Intersection[lst1, lst2]

CROSSREFS

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 16 2011

EXTENSIONS

Name clarified by Tanya Khovanova, Jun 23 2021

STATUS

approved