A384601 Numbers k such that T(k, 1) mod 3 = 1 and T(k, 2) mod 3 = 1, where T is the Wythoff array (A035513).

2, 8, 17, 26, 32, 41, 56, 65, 71, 80, 89, 95, 104, 110, 119, 128, 134, 143, 158, 167, 173, 182, 191, 197, 206, 221, 230, 236, 245, 260, 269, 275, 284, 293, 299, 308, 323, 332, 338, 347, 356, 362, 371, 377, 386, 395, 401, 410, 425, 434, 440, 449, 458, 464

Offset: 1

Author

Clark Kimberling, Jun 05 2025

Keywords

• nonn

Comments

This is one of 9 sets that partition the positive integers; see the Jun 04 2025 comment in A035513.

Examples

			(Row 8 of T) = (19,31,50,81,...).
((Row 8 of T) mod 3) = (1,1,2,0,...), so 8 is in the list.
		

Crossrefs

Cf. A035513, A384602.

Programs

Mathematica

w[n_] := {Floor[n*GoldenRatio] + n - 1, 2*Floor[n*GoldenRatio] + n - 1}
t = Table[Mod[w[n], 3], {n, 1, 500}];
Flatten[Position[t, {1, 1}]]   (* A384601 *)
Flatten[Position[t, {1, 2}]]   (* A384602 *)