A349282 a(n) is the least k such that A349281(k) = n.

1, 2, 4, 12, 36, 144, 576, 2880, 14400, 100800, 705600, 6350400, 45158400, 406425600, 3657830400, 40236134400, 442597478400, 5753767219200, 74798973849600, 1271582555443200, 21616903442534400, 410721165408153600, 7803702142754918400, 179485149283363123200, 4128158433517351833600

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..40

Example

a(2) = 4 since A349281(4) = 2 and A349281(k) != 2 for all k < 4.

Mathematica

f[p_, e_] := DivisorSigma[0, e]; d[1] = 0; d[n_] := Plus @@ f @@@ FactorInteger[n]; seq[len_, nmax_] := Module[{s = Table[0, {len}], k = 0, n = 1, i}, While[k < len && n < nmax, i = d[n] + 1; If[i <= len && s[[i]] == 0, k++; s[[i]] = n]; n++]; TakeWhile[s, # > 0 &]]; seq[11, 10^6]

Crossrefs

Cf. A349260, A349281.

Subsequence of A025487.

Sequence in context: A282165 A111942 A010551 * A276230 A393804 A003701

Adjacent sequences: A349279 A349280 A349281 * A349283 A349284 A349285

Keyword

nonn

Author

Amiram Eldar, Nov 13 2021

Status

approved