A096484 Integer part of the square root of (2n-1)-th decimal repunit.

1, 10, 105, 1054, 10540, 105409, 1054092, 10540925, 105409255, 1054092553, 10540925533, 105409255338, 1054092553389, 10540925533894, 105409255338945, 1054092553389459, 10540925533894597, 105409255338945977

Offset: 1

Author

Labos Elemer, Jun 24 2004

Keywords

• base
• nonn
• easy

Examples

			a(4) = floor(sqrt(1111111)) = 1054. 1111111 is the 7th decimal repunit.
		

Crossrefs

Cf. A000196, A002275, A096483.

Formula

a(n) = floor(sqrt((10^(2*n-1)-1)/9)).

a(n) = A000196(A002275(2*n-1)).

a(n) = A096483(2*n-1). - Jason Yuen, Aug 29 2024