Find the next term of the given series. 8, 39, 79, 394, 789, ?

The pattern alternates between two operations. From odd to even positions: multiply by 10 and add 5 (8×10+5=85, but pattern shows 39, 79×10+5=795, etc). From even to odd positions: multiply by 5 and subtract 1 (39×5-1=194, but 394×5-1=1969, so pattern is: even→odd: a_n×5-1. For 789 (odd position), next is even: 789×10+5=7945, but this doesn't match. The correct pattern is: even→odd: previous even ×5-1 gives next odd (39×5-1≠79). Re-analyzing: 39 is 8×5-1, 79 is 39×2+1, 394 is 79×5-1, 789 is 394×2+1, so next is 789×5-1=3944.