A094511 - OEIS

%I #14 Nov 30 2014 03:29:42

%S 2,1,4,8,3,5,6,16,10,9,7,17,11,12,13,32,18,20,14,24,19,21,15,33,22,25,

%T 23,26,27,28,29,64,34,36,37,40,35,41,30,48,38,44,39,42,43,45,31,65,50,

%U 49,46,56,51,52,47,66,53,54,55,57,58,59,60,128,68,72,69,80,67,73,70

%N Smallest number distinct from n, not occurring earlier and having in binary representation not more ones than n.

%C Permutation of the natural numbers: A094512(a(n))=a(A094512(n))=n.

%H Paul Tek, <a href="/A094511/b094511.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%o (Haskell)

%o import Data.List (delete)

%o a094511 n = a094511_list !! (n-1)

%o a094511_list = f 1 [1..] where

%o    f x zs = g zs where

%o      g (y:ys) = if y /= x && a000120 y <= wt

%o                    then y : f (x + 1) (delete y zs) else g ys

%o      wt = a000120 x

%o -- _Reinhard Zumkeller_, Nov 23 2014

%Y Cf. A007088, A000120, A094513, A094510.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, May 06 2004