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A362135
Indices of novel terms in A360179.
4
1, 3, 5, 7, 9, 12, 15, 17, 21, 25, 29, 31, 36, 41, 47, 52, 58, 64, 69, 74, 82, 87, 92, 100, 106, 112, 120, 128, 138, 145, 153, 160, 168, 176, 183, 189, 198, 209, 220, 233, 242, 252, 265, 277, 285, 294, 309, 325, 338, 349, 359, 371, 384, 400, 413, 430, 447, 459, 474, 492, 515, 533, 545, 557, 570, 594
OFFSET
1,2
COMMENTS
If we read A360179 as an irregular triangle of rows whose terms strictly increase, then a(n) is the index k such that A360179(k) is the last and largest term in row n.
A362128 is a subsequence of this sequence.
LINKS
MATHEMATICA
nn = 600;
c[_] := False; h[_] := 0; f[n_] := DivisorSigma[0, n];
a[1] = j = u = w = 1;
{1}~Join~Rest@ Reap[Do[
If[c[j],
k = j + f[u]; h[j]++; h[u]--,
k = f[j]; c[j] = True; h[j]++; Sow[n - 1] ];
u = Min[u, j]; Set[{a[n], q[k], j}, {k, True, k}];
While[h[u] == 0, u++], {n, 2, nn}] ][[-1, -1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Apr 10 2023
STATUS
approved