A347938 Primitive terms of A347935: terms of A347935 that are not multiples of other terms of A347935.

60, 72, 108, 168, 252, 264, 280, 312, 396, 400, 468, 588, 612, 684, 816, 828, 880, 912, 924, 1040, 1044, 1092, 1104, 1116, 1232, 1332, 1360, 1392, 1428, 1456, 1476, 1520, 1548, 1568, 1596, 1692, 1716, 1840, 1890, 1908, 1932, 2124, 2196, 2200, 2244, 2288, 2320

Offset

1,1

Comments

Since any positive multiple of a term of A347935 is also a term of A347935, the sequence A347935 consists of the positive multiple of this sequence.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

The first 10 terms of A347935 are 60, 72, 108, 120, 144, 168, 180, 216, 240, 252. 120, 180 and 240 are multiples of 60, 144 is a multiple of 72, and 216 is a multiple of 108 and therefore they are not terms of this sequence. So, this sequence begins with 60, 72, 108, 168, 252.

Mathematica

abQ[n_] := DivisorSigma[1, n] > 2*n; s[n_] := DivisorSum[n, # &, abQ[#] &]; q[n_] := s[n] > 2*n && AllTrue[Most @ Divisors[n], ! q[#] &]; Select[Range[3000], q]

Crossrefs

Subsequence of A005101 and A347935.

Cf. A071395, A091191, A187795.

Sequence in context: A335198 A335935 A347935 * A114837 A328149 A154548

Adjacent sequences: A347935 A347936 A347937 * A347939 A347940 A347941

Keyword

nonn

Author

Amiram Eldar, Sep 20 2021

Status

approved