A068001 Smallest number whose n-th power (A067457) starts with n.

1, 5, 7, 8, 9, 2, 5, 13, 46, 2, 19, 15, 6, 74, 12, 58, 4, 8, 5, 52, 6, 128, 85, 53, 15, 61, 113, 17, 55, 52, 83, 47, 147, 43, 297, 238, 63, 117, 51, 49, 145, 98, 219, 109, 48, 38, 114, 283, 423, 226, 334, 168, 38, 87, 91, 58, 189, 166, 42, 222, 92, 59, 133, 86, 544, 264, 5

Offset: 1

Author

Robert G. Wilson v, Feb 08 2002

Keywords

• base
• easy
• nonn

Examples

			a(3) = 7 because 7^3 = 343 which starts with 3 and there is no number less than 7 with this property.
		

Links

• Paolo P. Lava, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A051248, A067457.

Programs

Mathematica

Do[k = Floor[ Log[ 10, n] + 1]; While[ FromDigits[ Take[ IntegerDigits [k^n], Floor[ Log[ 10, n] + 1]]] != n, k++ ]; Print[k^n], {n, 1, 100} ]