A138466 a(1)=1; for n >= 2, a(n) = n - floor((1/2)*a(a(n-1))).
1, 2, 2, 3, 4, 5, 5, 6, 7, 8, 8, 9, 10, 10, 11, 12, 13, 13, 14, 15, 16, 16, 17, 18, 19, 19, 20, 21, 21, 22, 23, 24, 24, 25, 26, 27, 27, 28, 29, 30, 30, 31, 32, 32, 33, 34, 35, 35, 36, 37, 38, 38, 39, 40, 40, 41, 42, 43, 43, 44, 45, 46, 46, 47, 48, 49, 49, 50, 51, 51, 52, 53, 54
Offset: 1
Links
- Michel Dekking, Proof by Benoit Cloitre
Programs
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Mathematica
Floor[(Sqrt[3] - 1)*(Range[100] + 1)] (* Wesley Ivan Hurt, Jan 20 2024 *)
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PARI
a(n)=floor((sqrt(3)-1)*(n+1))
Formula
For n >= 1, a(n) = floor((sqrt(3)-1)*(n+1)).