# We can easily verify that none of the entries in the first seven
# rows of Pascal's triangle are divisible by 7:

#                  1
#                1    1
#             1    2    1
#           1    3    3   1
#         1   4    6    4   1
#       1   5   10   10   5   1
#     1   6  15   20   15   6   1

# However, if we check the first one hundred rows, we will find
# that only 2361 of the 5050 entries are not divisible by 7.

# Find the number of entries which are not divisible by 7 in the
# first one billion (10^9) rows of Pascal's triangle.
# We can easily verify that none of the entries in the first seven
# rows of Pascal's triangle are divisible by 7:

#                  1
#                1    1
#             1    2    1
#           1    3    3   1
#         1   4    6    4   1
#       1   5   10   10   5   1
#     1   6  15   20   15   6   1

# However, if we check the first one hundred rows, we will find
# that only 2361 of the 5050 entries are not divisible by 7.

# Find the number of entries which are not divisible by 7 in the
# first one billion (10^9) rows of Pascal's triangle.
# We can easily verify that none of the entries in the first seven # rows of Pascal's triangle are divisible by 7: #                  1 #                1    1 #             1    2    1 #           1    3    3   1 #         1   4    6    4   1 #       1   5   10   10   5   1 #     1   6  15   20   15   6   1 # However, if we check the first one hundred rows, we will find # that only 2361 of the 5050 entries are not divisible by 7. # Find the number of entries which are not divisible by 7 in the # first one billion (10^9) rows of Pascal's triangle.