A066249 Inverse permutation to A066248.

3, 1, 5, 2, 7, 4, 8, 6, 9, 10, 11, 12, 13, 16, 14, 18, 15, 22, 17, 28, 19, 30, 20, 36, 21, 40, 23, 42, 24, 46, 25, 52, 26, 58, 27, 60, 29, 66, 31, 70, 32, 72, 33, 78, 34, 82, 35, 88, 37, 96, 38, 100, 39, 102, 41, 106, 43, 108, 44, 112, 45, 126, 47, 130, 48, 136, 49, 138, 50

Offset: 1

Author

Reinhard Zumkeller, Dec 09 2001

Keywords

• nonn

Comments

Permutation of natural numbers.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers.

Crossrefs

Cf. A066248, A000040, A002808, A066251, A066253.

Programs

Mathematica

seq[nmax_] := Module[{p = Prime[Range[nmax]]}, Riffle[Take[Complement[Range[2, p[[-1]]], p] - 1, Length[p]], p - 1]]; seq[35] (* Amiram Eldar, Mar 19 2025 *)

Formula

a(n) = (if n is even then A000040(n/2) else A002808((n+1)/2)) - 1.