A101905 a(1) = 1; a(n+1) = A101261(2n).

1, 2, 4, 3, 8, 5, 9, 6, 16, 7, 14, 10, 21, 11, 19, 12, 32, 13, 24, 15, 34, 17, 30, 18, 45, 20, 36, 22, 47, 23, 40, 25, 64, 26, 44, 27, 59, 28, 51, 29, 74, 31, 56, 33, 73, 35, 61, 37, 93, 38, 67, 39, 87, 41, 72, 42, 103, 43, 78, 46, 99, 48, 83, 49, 128, 50, 88, 52, 111, 53, 92

Offset

1,2

Comments

Sequence is a permutation of the positive integers.

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Maple

A101261 := proc(nmax) local a, n, anex ; a := [1, 2] ; while nops(a) < nmax do if nops(a) mod 2 = 0 then a := [op(a), 1] ; else n := (nops(a)+1)/2 ; n := op(n, a) ; anex := 2 ; while anex in a or n > 1 do if not anex in a then n := n-1 ; fi ; anex := anex+1 ; od ; a := [op(a), anex] ; fi ; od ; RETURN(a) ; end: A101905 := proc(nmax) local a, n, anex ; a := A101261(2*nmax) ; for n from 2*nmax-1 to 3 by -2 do a := subsop(n=NULL, a) ; od ; RETURN(a) ; end: A101905(80) ; # R. J. Mathar, May 02 2007

Mathematica

a = {1}; Do[AppendTo[a, Complement[Range[Max[a] + (d = If[EvenQ[n], 1, a[[(n + 1)/2]]])], a][[d]]], {n, 2, 71}]; a (* Ivan Neretin, May 03 2015 *)

Crossrefs

Cf. A101261, A101906.

Sequence in context: A331585 A191729 A075378 * A297075 A306458 A287637

Adjacent sequences: A101902 A101903 A101904 * A101906 A101907 A101908

Keyword

easy,nonn

Author

Leroy Quet, Dec 20 2004

Extensions

More terms from R. J. Mathar, May 02 2007

Status

approved