cp's OEIS Frontend

A096780 Inverse of A075383.

%I A096780 #17 Jan 29 2021 14:46:02
%S A096780 1,2,4,3,11,5,22,7,6,12,56,8,79,23,13,9,137,16,172,10,24,57,254,17,14,
%T A096780 80,37,25,407,15,466,29,58,138,26,18,667,173,81,30,821,19,904,59,38,
%U A096780 255,1082,20,27,46,139,82,1379,21,60,28,174,408,1712,47,1831,467,39
%N A096780 Inverse of A075383.
%C A096780 Integer permutation: a(A075383(n)) = A075383(a(n)) = n;
%C A096780 A096782(n) = a(a(n)).
%C A096780 For any n > 0, A002024(a(n)) divides n. - _Rémy Sigrist_, Jan 29 2021
%H A096780 Reinhard Zumkeller, <a href="/A096780/b096780.txt">Table of n, a(n) for n = 1..1000</a>
%H A096780 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%t A096780 nmax = 100; row[1] = {1}; row[n_] := row[n] = (For[rows = Join[row /@ Range[n-1]]; ro = {}; k = n, Length[ro] < n, k = k+n, If[FreeQ[rows, k], AppendTo[ro, k]]]; ro);
%t A096780 A075383 = Array[row, nmax] // Flatten;
%t A096780 a[n_] := FirstPosition[A075383, n][[1]];
%t A096780 Array[a, nmax] (* _Jean-François Alcover_, Apr 28 2017 *)
%o A096780 (Haskell)
%o A096780 import Data.List (elemIndex); import Data.Maybe (fromJust)
%o A096780 a096780 = (+ 1) . fromJust . (`elemIndex` a075383_list)
%o A096780 -- _Reinhard Zumkeller_, Nov 29 2015
%Y A096780 Cf. A002024, A075383, A096782.
%K A096780 nonn
%O A096780 1,2
%A A096780 _Reinhard Zumkeller_, Jul 09 2004