A035073 a(n) is root of square starting with digit 6: first term of runs.

8, 25, 78, 245, 775, 2450, 7746, 24495, 77460, 244949, 774597, 2449490, 7745967, 24494898, 77459667, 244948975, 774596670, 2449489743, 7745966693, 24494897428, 77459666925, 244948974279, 774596669242, 2449489742784, 7745966692415, 24494897427832, 77459666924149

Offset: 1

Author

Patrick De Geest, Nov 15 1998

Keywords

• nonn
• base

Crossrefs

Subsequence of A045860.

Cf. A067576 (squares), A035076 (2..9).

Programs

Python

from math import isqrt
def a(n): return isqrt(6*10**n) + 1
print([a(n) for n in range(1, 28)]) # Michael S. Branicky, Aug 25 2021

Formula

a(n) = ceiling(sqrt(6*10^n)), n > 0.