A226569 Inverse permutation to A226532.

1, 2, 6, 4, 15, 3, 35, 8, 36, 30, 77, 24, 143, 70, 10, 16, 221, 72, 323, 60, 210, 154, 437, 12, 225, 286, 216, 140, 667, 5, 899, 32, 462, 442, 21, 9, 1147, 646, 858, 120, 1517, 105, 1763, 308, 540, 874, 2021, 96, 1225, 450, 1326, 572, 2491, 108, 1155, 280

Offset: 1

Author

Reinhard Zumkeller, Jun 11 2013

Keywords

• nonn
• look

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A000079 (fixed points).

Programs

Haskell

-- import Data.List (elemIndex); import Data.Maybe (fromJust)
a226569 = (+ 1) . fromJust . (`elemIndex` a226532_list)

Maple

f:= proc(n) local F,Fp,V,m,j,r;
  F:= ifactors(n)[2];
  Fp:= map(numtheory:-pi, F[..,1]);
  m:= max(Fp);
  V:= Vector(m);
  for j from 1 to nops(F) do V[Fp[j]]:= F[j,2] od:
  r:= ithprime(m)^V[m];
  for j from m-1 to 1 by -1 do r:= r * ithprime(j)^Bits:-Xor(V[j],V[j+1]) od;
  r
end proc:
f(1):= 1:
map(f, [$1..100]); # Robert Israel, Aug 21 2025

Formula

If k = Prod_{i=1..m} prime(i)^e(i), then a(k) = prime(m)^e(m) * Prod_{i=1..m-1} prime(i)^(e(i) xor e(i+1)). - Robert Israel, Aug 21 2025