OFFSET
1,2
COMMENTS
Conjecture: This is a permutation of the positive integers.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..17878 (All terms that appear in a(n) for n = 1..2^24)
MATHEMATICA
nn = 1000; c[_] = False; q[_] = 0; f[n_] := DivisorSigma[0, n]; a[1] = m = 1; Do[(If[c[#], a[n] = # + f[a[m]] ; m++, a[n] = f[#] ]; c[#] = True; If[q[#] == 0, q[#] = n - 1]) &[a[n - 1]], {n, 2, nn}]; TakeWhile[Array[q, nn], # > 0 &] (* Michael De Vlieger, Apr 08 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 08 2023
STATUS
approved