A067478 Smallest n-digit square starting with 8.

81, 841, 8100, 80089, 801025, 8003241, 80013025, 800041225, 8000050249, 80000162649, 800001447184, 8000004951184, 80000001609984, 800000042569984, 8000000160998400, 80000000297200369, 800000000000150481, 8000000001435765625, 80000000000015048100

Offset: 2

Author

Amarnath Murthy, Feb 09 2002

Keywords

• nonn
• base
• easy

Crossrefs

Cf. A000290, A035075 (roots), A045791, A067479 (2..9).

Programs

Mathematica

nS[n_] := Module[{lr = Floor[Sqrt[n]]}, If[lr^2==n, lr^2, (lr + 1)^2]]; Table[nS[8 10^i], {i, 0, 20}]

Formula

a(n) = ceiling(sqrt(8*10^(n-1)))^2. - Sascha Kurz, Mar 18 2002

Extensions

More terms from Harvey P. Dale, Feb 17 2002

Incorrect a(1) removed by Jon E. Schoenfield, Mar 21 2021