A017965 Powers of sqrt(20) rounded to nearest integer.

1, 4, 20, 89, 400, 1789, 8000, 35777, 160000, 715542, 3200000, 14310835, 64000000, 286216701, 1280000000, 5724334022, 25600000000, 114486680448, 512000000000, 2289733608960, 10240000000000, 45794672179196

Offset

0,2

Links

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

Mathematica

Floor[(Sqrt[20]^Range[0, 25]+1/2)] (* Harvey P. Dale, Aug 08 2011 *)

Prog

(Magma) [(Floor((Sqrt(20)^n)+1/2)): n in [0..30]]; // Vincenzo Librandi, Aug 09 2011
(PARI) a(n)=round(sqrt(20)^n) \\ Charles R Greathouse IV, Nov 18 2011

Crossrefs

Sequence in context: A093357 A027156 A017964 * A180284 A065180 A229245

Adjacent sequences: A017962 A017963 A017964 * A017966 A017967 A017968

Keyword

nonn

Author

N. J. A. Sloane

Status

approved