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A018072
Powers of fourth root of 10 rounded down.
3
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
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
KEYWORD
nonn,easy
EXTENSIONS
A few additional terms from Alonso del Arte, Jan 26 2013
STATUS
approved