A018151 - OEIS

%I #17 Jun 22 2024 18:02:45

%S 1,2,3,5,8,13,22,36,61,101,169,282,471,788,1315,2197,3670,6129,10238,

%T 17100,28561,47705,79680,133088,222294,371293,620162,1035843,1730146,

%U 2889824,4826809,8062111,13465964

%N Powers of fifth root of 13 rounded to nearest integer.

%H Paolo Xausa, <a href="/A018151/b018151.txt">Table of n, a(n) for n = 0..1000</a>

%t Round[(13^(1/5))^Range[0, 50]] (* _Paolo Xausa_, Jun 22 2024 *)

%o (Python)

%o from gmpy2 import iroot_rem

%o def A018151(n):

%o     i, j = iroot_rem(13**n,5)

%o     return int(i)+int(j<<5>=10*i*((i*((i*(i+1)<<1)+1)<<2)+1)+1) # _Chai Wah Wu_, Jun 20 2024

%Y Cf. A011098.

%K nonn

%O 0,2

%A _N. J. A. Sloane_