A363692 Terms of A363690 with a record number of divisors.

3, 6, 12, 24, 36, 48, 72, 144, 168, 288, 336, 420, 840, 1680, 3360, 6720, 7560, 15120, 30240, 60480, 95760, 120960, 176400, 191520, 257040, 352800, 383040, 514080, 1028160, 1681680, 2056320, 2998800, 3112200, 5525520, 5997600, 6224400, 8353800, 12448800, 16216200

Offset

1,1

Comments

The corresponding record values are 2, 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 32, 40, 48, ... .

Links

David A. Corneth, Table of n, a(n) for n = 1..160 (first 56 terms from Amiram Eldar)

Formula

a(n) <= 2*a(n-1) for n >= 2. - David A. Corneth, Jun 18 2023

Mathematica

seq[kmax_] := Module[{s = {}, dm = 0, d1}, Do[d1 = DivisorSigma[0, k]; If[d1 > dm && DivisorSum[k, Boole[BitOr[#, k] == k] &] == 2, dm = d1; AppendTo[s, k]], {k, 1, kmax}]; s]; seq[10^5]

Prog

(PARI) lista(kmax) = {my(dm = 0, d1); for(k = 1, kmax, d1 = numdiv(k); if(d1 > dm && sumdiv(k, d, bitor(d, k) == k) == 2, dm = d1; print1(k, ", "))); }

Crossrefs

Cf. A000005, A359082, A359083, A361937, A363690, A363693.

Sequence in context: A003204 A038620 A250300 * A330132 A039695 A079079

Adjacent sequences: A363689 A363690 A363691 * A363693 A363694 A363695

Keyword

nonn,base

Author

Amiram Eldar, Jun 16 2023

Status

approved