In each of the following number series, one of the numbers is wrong. Find it out. 68, 70, 73, 78, 82, 88

The series follows an increasing addition pattern: +2, +3, +5, +4, +6. Starting from 68: 68+2=70, 70+3=73, 73+5=78, 78+4=82, 82+6=88. The number 78 should be checked. Actually, the pattern might be +2, +3, +5, +4, +6 where the additions themselves follow a pattern. If we expect +2, +3, +4, +5, +6, then 78 breaks it (we have +5 instead of +4).