A018117 Powers of fifth root of 2 rounded down.

1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 8, 9, 10, 12, 13, 16, 18, 21, 24, 27, 32, 36, 42, 48, 55, 64, 73, 84, 97, 111, 128, 147, 168, 194, 222, 256, 294, 337, 388, 445, 512, 588, 675, 776, 891, 1024, 1176, 1351, 1552, 1782, 2048, 2352, 2702, 3104, 3565, 4096

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Amiram Eldar, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A017910, A017979, A018048.

Programs

Mathematica

a[n_] := Floor[2^(n/5)]; Array[a, 100, 0] (* Amiram Eldar, Apr 04 2025 *)

PARI

a(n) = sqrtnint(2^n, 5) \\ Amiram Eldar, Apr 04 2025