N Hegyvári - European Journal of Combinatorics, 1996 - infona.pl
Folkman's theorem states that ifA={a 1< a 2<...} satisfyingA (n)> n 1/2+ ε, whereA (n)= ai=< n
1), thenP (A)={ai 1+ ai 2+...+ ais: i 1< i 2<...< is; s N; aij A} contains an infinite arithmetic …