A192819 Numbers which are both abundant (A005101) and anti-abundant (A192268).

12, 18, 20, 30, 40, 42, 48, 60, 66, 70, 72, 78, 80, 84, 88, 90, 100, 102, 104, 108, 112, 120, 126, 132, 138, 140, 144, 150, 160, 162, 168, 176, 180, 186, 192, 196, 198, 200, 204, 208, 210, 220, 222, 228, 234, 240, 252, 258, 260, 264, 270, 272, 276, 280, 282, 288

Offset

1,1

Comments

This is to abundant numbers as A192818 is to deficient numbers.

Links

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

Formula

A005101 INTERSECTION A192268.

Mathematica

q[n_] := Total[Cases[Range[2, n - 1], _?(Abs[Mod[n, #] - #/2] < 1 &)]] > n && DivisorSigma[1, n] > 2*n; Select[Range[300], q] (* Amiram Eldar, Jan 13 2022 after Michael De Vlieger at A066417 *)

Crossrefs

Cf. A005101, A066417, A192268, A192818.

Sequence in context: A381546 A333928 A357695 * A181487 A091191 A357696

Adjacent sequences: A192816 A192817 A192818 * A192820 A192821 A192822

Keyword

nonn

Author

Jonathan Vos Post, Jul 11 2011

Extensions

Missing term a(4) inserted and more terms added by Amiram Eldar, Jan 13 2022

Status

approved