A088723 - OEIS

A088723

Numbers k with at least one divisor d>1 such that d+1 also divides k.

6, 12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66, 72, 78, 80, 84, 90, 96, 100, 102, 108, 110, 112, 114, 120, 126, 132, 138, 140, 144, 150, 156, 160, 162, 168, 174, 180, 182, 186, 192, 198, 200, 204, 210, 216, 220, 222, 224, 228, 234, 240, 246, 252, 258, 260

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OFFSET

1,1

COMMENTS

A088722(a(n))>0; complement of A088725.

Complement of A132895 relative to A005843, the even numbers. - Chandler

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[300], MemberQ[Differences[Select[Divisors[#], #>1&]], 1]&] (* Harvey P. Dale, Apr 03 2011 *)

PROG

(Haskell)