a+b = c/2 c = nr. par
c = 8 a + b = 4 a = 1 b = 3 abc = 138
a= 3 b = 1 abc = 318
a = 4 b = 0 abc = 408
c = 6 a + b = 3 a = 1 b = 2 abc = 126
a = 2 b = 1 abc = 216
a = 3 b = 0 abc = 306
c = 4 a + b = 2 a = 2 b = 0 abc = 204
c = 2 a + b = 1 a = 1 b = 0 abc = 102