A341255 Let f(n) = floor(r*floor(r*n)) = A341254(n), where r = (2 + sqrt(5))/2. Let a(1) = 1. Then a(n) = f(a(n-1)) for n >= 2.

1, 4, 16, 69, 309, 1385, 6212, 27866, 125008, 560793, 2515754, 11285842, 50629052, 227125366, 1018899829, 4570853893, 20505161277, 91987547377, 412662390616, 1851231536059, 8304750512850, 37255675336820, 167131492108634, 749763234780300, 3363488838254558

Offset: 1

Author

Clark Kimberling, Feb 13 2021

Keywords

• nonn
• easy

Crossrefs

Cf. A339828, A341240, A341249.

Programs

Mathematica

z = 40; u = GoldenRatio;
r = u + 1/2; f[x_] := Floor[r*Floor[r*x]];
Table[f[n], {n, 1, z}]  (* A341254 *)
a[1] = 1; a[n_] := f[a[n - 1]];
Table[a[n], {n, 1, z}]  (* A341255 *)