A018072 Powers of fourth root of 10 rounded down.

1, 1, 3, 5, 10, 17, 31, 56, 100, 177, 316, 562, 1000, 1778, 3162, 5623, 10000, 17782, 31622, 56234, 100000, 177827, 316227, 562341, 1000000, 1778279, 3162277, 5623413, 10000000, 17782794, 31622776, 56234132, 100000000, 177827941, 316227766, 562341325, 1000000000, 1778279410

Offset

0,3

Links

Table of n, a(n) for n=0..37.

Example

a(2) = 3 because 10^(2/4) = 10^(1/2) = sqrt(10) = 3.16228...
a(3) = 5 because 10^(3/4) = 5.62341...
a(4) = 10 because 10^(4/4) = 10^1 = 10.
a(5) = 17 because 10^(5/4) = 17.78279...

Mathematica

Table[Floor[10^(n/4)], {n, 0, 39}] (* Alonso del Arte, Jan 26 2013 *)
Floor[Surd[10, 4]^Range[0, 40]] (* Harvey P. Dale, Oct 26 2019 *)

Prog

(PARI) a(n)=sqrtint(sqrtint(10^n)) \\ Charles R Greathouse IV, Jan 27 2013

Crossrefs

Cf. A017934, A011007, A010467.

Sequence in context: A079934 A215004 A005403 * A090170 A301751 A054166

Adjacent sequences: A018069 A018070 A018071 * A018073 A018074 A018075

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

A few additional terms from Alonso del Arte, Jan 26 2013

Status

approved