Ramsey数的性质 (1)R(a1b)=R(b,a),R(a,2)=R(2, (2)R(b)≤R(a-1,b)+R(nb-1) 性质(2)给出上界 9=R(3,4)≤R(2,4)+R(3,3)=4+6=10 18=R(4,4)≤R(3,4)+R(4,3)=9+9=18 25=R(4,5)≤R3,5)+R(4,4)=14+18=32 R(3,10)≤R2,10)+R(3,9)=10+36=46 R(3,10)≤438 (1) R(a,b)=R(b,a), R(a,2) = R(2,a)=a (2) R(a,b) ≤ R(a-1,b) + R(a,b-1) 性质 (2) 给出上界 9 = R(3,4) ≤ R(2,4) + R(3,3) = 4 + 6 = 10 18 = R(4,4) ≤ R(3,4) + R(4,3) = 9 + 9 = 18 25 = R(4,5) ≤ R(3,5) + R(4,4) = 14 + 18 = 32 R(3,10) ≤ R(2,10) + R(3,9) = 10 + 36 = 46 R(3,10) ≤ 43 Ramsey数的性质