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

1,1

Links

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

Example

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

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

Crossrefs

Subsequence of A308053.

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

Sequence in context: A204603 A176382 A347937 * A092017 A238079 A209958

Adjacent sequences: A339934 A339935 A339936 * A339938 A339939 A339940

Keyword

nonn

Author

Amiram Eldar, Dec 23 2020

Status

approved