A018102 Powers of fourth root of 20 rounded down.

1, 2, 4, 9, 20, 42, 89, 189, 400, 845, 1788, 3782, 8000, 16917, 35777, 75659, 160000, 338358, 715541, 1513186, 3200000, 6767176, 14310835, 30263731, 64000000, 135343521, 286216701, 605274629, 1280000000, 2706870434, 5724334022, 12105492595, 25600000000

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Mathematica

Floor[(Power[20, (4)^-1])^Range[0, 30]]  (* Harvey P. Dale, Apr 25 2011 *)

Prog

(Magma) [Floor((20^(1/4))^n) : n in [0..35]]; // Vincenzo Librandi, May 30 2025
(PARI) a(n) = sqrtnint(20^n, 4); \\ Michel Marcus, May 30 2025

Crossrefs

Cf. A011016, A018103, A018104.

Sequence in context: A240047 A090166 A101338 * A018103 A350092 A175104

Adjacent sequences: A018099 A018100 A018101 * A018103 A018104 A018105

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved