A050001 - OEIS

%I #13 Jul 13 2013 12:02:14

%S 1,5,2,4,19,6,16,26,3,18,23,28,10,15,20,25,61,7,12,35,17,22,76,27,45,

%T 130,9,14,135,37,73,91,24,60,127,29,47,65,11,34,52,70,88,478,21,75,

%U 124,93,359,44,62,129,594,8,49,116,13,134,506,36,54,431,72,90,139,480,41,59

%N a(n)=position of n in A050000.

%C Inverse permutation to A050000: a(A050000(n)) = A050000(a(n)) = n.

%H Reinhard Zumkeller, <a href="/A050001/b050001.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>

%o (Haskell)

%o import Data.List (elemIndex)

%o import Data.Maybe (fromJust)

%o a050001 n = (fromJust $ elemIndex n a050000_list) + 1

%o -- _Reinhard Zumkeller_, Nov 13 2011

%Y a(n) = k <=> A050000(k) = n.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_

%E More terms from _Ray Chandler_, Nov 16 2003