A018157 Powers of fifth root of 15 rounded to nearest integer.

1, 2, 3, 5, 9, 15, 26, 44, 76, 131, 225, 387, 665, 1142, 1964, 3375, 5801, 9970, 17137, 29454, 50625, 87013, 149555, 257051, 441813, 759375, 1305192, 2243328, 3855769, 6627188, 11390625, 19577886, 33649922

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Paolo Xausa, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A011100.

Programs

Mathematica

Round[(15^(1/5))^Range[0, 50]] (* Paolo Xausa, Jul 01 2024 *)

Python

from gmpy2 import iroot_rem
def A018157(n):
    i, j = iroot_rem(15**n,5)
    return int(i)+int(j<<5>=10*i*((i*((i*(i+1)<<1)+1)<<2)+1)+1) # Chai Wah Wu, Jun 20 2024