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
Examples
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...
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..2000
Programs
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Magma
[Floor(10^(n/4)): n in [0..37]]; // Vincenzo Librandi, May 30 2025
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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 *) -
PARI
a(n)=sqrtint(sqrtint(10^n)) \\ Charles R Greathouse IV, Jan 27 2013
Extensions
A few additional terms from Alonso del Arte, Jan 26 2013