A017949 Powers of sqrt(15) rounded down.

1, 3, 15, 58, 225, 871, 3375, 13071, 50625, 196069, 759375, 2941046, 11390625, 44115700, 170859375, 661735513, 2562890625, 9926032708, 38443359375, 148890490631, 576650390625, 2233357359474, 8649755859375

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..800

Crossrefs

Cf. A010472 (sqrt(15)).

Programs

Magma

[Floor(Sqrt(15^n)): n in [0..30]]; // Vincenzo Librandi, Jun 24 2011

Mathematica

Floor[(Sqrt[15])^Range[0,30]] (* Harvey P. Dale, Jul 03 2020 *)

PARI

a(n)=sqrtint(15^n) \\ Charles R Greathouse IV, Nov 18 2011

Formula

a(n) = floor(sqrt(15^n)). - Vincenzo Librandi, Jun 24 2011