How many 7s are there in the following sequence, which are immediately preceded by 1 and not immediately followed by 3 ?
9, 8, 5, 1, 7, 3, 1, 7, 6, 5, 6, 3, 7, 7, 1, 4, 6, 1, 7, 5, 9, 3, 1, 7, 4, 4, 6, 1, 7, 3, 3, 7, 8, 1, 7, 2
1
1
2
2
3
3
4
4
How many 7s are there in the following sequence, which are immediately preceded by 1 and not immediately followed by 3 ?
9, 8, 5, 1, 7, 3, 1, 7, 6, 5, 6, 3, 7, 7, 1, 4, 6, 1, 7, 5, 9, 3, 1, 7, 4, 4, 6, 1, 7, 3, 3, 7, 8, 1, 7, 2