A336443 Primitive terms of A336442: terms k of A336442 such that none of the proper divisors of k are in A336442.

60, 140, 210, 315, 462, 504, 616, 693, 728, 770, 792, 819, 910, 936, 990, 1001, 1092, 1144, 1170, 1287, 1430, 1530, 1683, 1716, 1870, 1989, 2090, 2142, 2145, 2210, 2244, 2431, 2448, 2470, 2508, 2618, 2652, 2717, 2805, 2926, 2964, 2992, 3094, 3135, 3230, 3315

Offset

1,1

Comments

Any term of A336442 is a multiple of at least one term of this sequence.

Links

David A. Corneth, Table of n, a(n) for n = 1..10347

Example

60 is a term since it is a term of A336442 but none of its proper divisors are in A336442.
120 is not a term: although it is in A336442, it is a multiple of 60 which is also a term of A336442.

Mathematica

divQ[n_] := AnyTrue[Subsets[Divisors[n], {3}], And @@ CoprimeQ @@@ Subsets[#, {2}] && #[[3]] < 2 #[[1]] &]; primQ[n_] := divQ[n] && AllTrue[Most[Divisors[n]], ! divQ[#] &]; Select[Range[3333], primQ]

Crossrefs

Analogous to A302022 as A336442 is analogous to A005279.

Sequence in context: A246474 A334407 A336628 * A252954 A221990 A043478

Adjacent sequences: A336440 A336441 A336442 * A336444 A336445 A336446

Keyword

nonn

Author

Amiram Eldar, Jul 21 2020

Status

approved