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A283769 Numbers k such that L(k) = 0 mod 3, where L = A000201 = lower Wythoff sequence. 3

%I

%S 2,4,6,8,13,15,17,19,21,26,28,30,32,39,41,43,45,52,54,56,58,65,67,69,

%T 71,78,80,82,84,89,91,93,95,97,102,104,106,108,110,115,117,119,121,

%U 128,130,132,134,141,143,145,147,154,156,158,160,167,169,171,173

%N Numbers k such that L(k) = 0 mod 3, where L = A000201 = lower Wythoff sequence.

%C The sequences A283769, A283770, A283771 partition the positive integers.

%H Clark Kimberling, <a href="/A283769/b283769.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n+1) - a(n) is in {2,5,7} for every n.

%t r = GoldenRatio; z = 350; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 3];

%t Flatten[Position[u, 0]] (* A283769 *)

%t Flatten[Position[u, 1]] (* A283770 *)

%t Flatten[Position[u, 2]] (* A283771 *)

%o (PARI) r = (1 + sqrt(5))/2;

%o for(n=1, 351, if(floor(n*r)%3==0, print1(n, ", "))) \\ _Indranil Ghosh_, Mar 19 2017

%o (Python)

%o import math

%o from sympy import sqrt

%o r = (1 + sqrt(5))/2

%o [n for n in range(1, 351) if int(math.floor(n*r)) % 3 == 0] # _Indranil Ghosh_, Mar 19 2017

%Y Cf. A000201, A001622, A283770, A283771.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Mar 18 2017

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Last modified September 21 07:28 EDT 2021. Contains 347596 sequences. (Running on oeis4.)