A122398 Sequence is inverse permutation to A122397.

1, 2, 3, 4, 8, 5, 11, 7, 12, 6, 18, 14, 21, 9, 10, 17, 32, 15, 35, 28, 13, 16, 40, 22, 27, 19, 24, 31, 49, 25, 56, 45, 20, 30, 29, 36, 68, 33, 23, 41, 73, 26, 82, 48, 39, 38, 83, 44, 55, 46, 34, 61, 97, 43, 50, 57, 37, 47, 105, 52, 116, 54, 53, 64, 63, 59, 123, 69, 42, 62, 132

Offset

1,2

Comments

Sequence is probably a permutation of the positive integers.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

A[1]:= 1: A[2]:= 2: A[3]:= 3: B[1]:=1: B[2]:= 2: B[3]:= 3:
S:= {$4..300}:
for n from 4 do
  P:= numtheory:-factorset(A[n-2]);
  for s in S do
    if member(igcd(s, A[n-2]), P) then
      A[n]:= s; B[s]:= n; S:= S minus {s}; break
    fi
  od;
  if not assigned(A[n]) then break fi;
od:
seq(B[i], i=1..S[1]-1); # Robert Israel, Jan 04 2023

Crossrefs

Cf. A122397.

Sequence in context: A137623 A358875 A191541 * A329567 A326487 A253562

Adjacent sequences: A122395 A122396 A122397 * A122399 A122400 A122401

Keyword

nonn

Author

Leroy Quet, Aug 31 2006

Extensions

Extended by Ray Chandler, Sep 05 2006

Status

approved