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Input interpretation:

prove | 9^n - 1 is  divisible by 4 | method | mathematical induction\nassuming | n>0


Result:

9^n - 1 is divisible by 4 for n>0 and n element Z


Values:

n | 1 | 2 | 3 | 4 | 5\n9^n - 1 | 8 | 80 | 728 | 6560 | 59048

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