A259570 - OEIS

%I #4 Jun 30 2015 15:20:49

%S 1,2,4,3,5,6,8,7,9,12,10,11,13,14,16,15,17,18,20,19,21,22,24,25,23,27,

%T 30,26,29,28,31,32,34,33,35,36,38,37,40,41,39,44,42,43,45,48,46,47,49,

%U 51,53,52,50,56,54,55,57,58,60,61,59,65,62,67,63,64,68

%N Smallest m such that A259565(m) = 2*n-1.

%C  Sequence is a permutation of the natural numbers iff A259565 is a permutation of the odd numbers;

%C A259565(a(n)) = 2*n-1.

%H Reinhard Zumkeller, <a href="/A259570/b259570.txt">Table of n, a(n) for n = 1..10000</a>

%o (Haskell)

%o import Data.List (elemIndex); import Data.Maybe (fromJust)

%o a259570 = (+ 1) . fromJust . (`elemIndex` a259565_list) . subtract 1 . (* 2)

%Y Cf. A259565.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Jun 30 2015