A240676 Number of digits in the decimal expansion of n^7.

1, 1, 3, 4, 5, 5, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13

Offset: 0

Author

Michelle Tu, Apr 28 2014

Keywords

• nonn
• base
• easy

Examples

			a(1) = 1, because 1^7 = 1.
a(2) = 4, because 2^7 = 1024.
		

Programs

PARI

a(n)=max(#digits(n^7),1) \\ Charles R Greathouse IV, May 12 2014

Formula

a(n) = A055642(n^7) = A055642(A001015(n)).