A339937 Numbers k such that k and k+1 are both coreful abundant numbers (A308053).

2282175, 33350624, 46734975, 86424975, 87152624, 105674624, 126114975, 169707824, 179762624, 214491375, 221370975, 235857824, 266022224, 270586575, 278524575, 297774224, 360021375, 372683024, 380858624, 395715375, 425840624, 470624175, 489873824, 503963775

Offset: 1

Author

Amiram Eldar, Dec 23 2020

Keywords

• nonn

Examples

			2282175 is a term since 2282175 and 2282176 are both coreful abundant numbers.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1000

Crossrefs

Subsequence of A308053.

Similar sequences: A096399, A283418, A318167, A327635, A327942, A330872, A331412, A333951.

Programs

Mathematica

f[p_, e_] := (p^(e + 1) - 1)/(p - 1) - 1; s[1] = 1; s[n_] := Times @@ (f @@@ FactorInteger[n]); abQ[n_] := s[n] > 2*n; q1 = False; seq = {}; Do[q2 = abQ[n]; If[q1 && q2, AppendTo[seq, n - 1]]; q1 = q2, {n, 2, 10^8}]; seq