OFFSET
1,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..40000
Michael De Vlieger, Labeled scatterplot of A360179(n), n = 1..300, showing a(n) in small red dots, and A360179(n) in large red when A360179(n) = a(n-1).
MATHEMATICA
nn = 120; c[_] := False; q[_] := False; h[_] := 0; f[n_] := DivisorSigma[0, n];
a[1] = j = u = w = 1;
{2}~Join~Reap[Do[
If[c[j],
k = j + f[u]; h[j]++; h[u]--,
k = f[j]; c[j] = True; h[j]++ ];
u = Min[u, j]; Set[{a[n], q[k], j}, {k, True, k}];
While[h[u] == 0, u++]; If[k == w, While[q[w], w++]];
Sow[w], {n, 2, nn}] ][[-1, -1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Apr 10 2023
STATUS
approved