A065654 Fixed points for A065652, a permutation of the natural numbers.

0, 1, 2, 4, 8, 24, 80, 784, 8288, 1053024, 115519040, 2186083514944, 26210587691915648, 9556921325803348132669824, 1373760651292040932579353684066560, 182669489453303120238622839813317479832750842872064

Offset: 0

Author

Reinhard Zumkeller, Nov 10 2001

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 0..23

Crossrefs

Cf. A065652, A065653.

Programs

Mathematica

f[n_] := f[n] = If[n < 2, n, f[n - 2]^2 + 2]; a[n_] := (f[n] + f[n + 1] - 1)/2; Array[a, 15, 0] (* Amiram Eldar, Mar 19 2025 *)

Formula

a(n) = (A065653(n) + A065653(n+1) - 1) / 2.