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A334166
Numbers k having a divisor d, such that d*k is a Zumkeller number (A083207).
2
6, 10, 12, 14, 18, 20, 24, 28, 30, 36, 40, 42, 44, 48, 50, 52, 54, 56, 60, 66, 68, 70, 72, 76, 78, 80, 84, 88, 90, 92, 96, 98, 100, 102, 104, 105, 108, 110, 112, 114, 116, 120, 124, 126, 130, 132, 136, 138, 140, 144, 150, 152, 154, 156, 160, 162, 168, 170, 174, 176, 180, 182, 184, 186, 190
OFFSET
1,1
COMMENTS
Conjecture: The difference between two consecutive terms is 6 at most.
LINKS
EXAMPLE
2 is a divisor of 10 and 10 is not a Zumkeller number, but 2*10 = 20 is a Zumkeller number, therefore 10 is in the sequence.
MATHEMATICA
zQ[n_]:=Module[{d=Divisors[n], t, ds, x}, ds=Plus@@d; If[Mod[ds, 2]>0, False, t=CoefficientList[Product[1+x^i, {i, d}], x]; t[[1+ds/2]]>0]]; fQ[n_]:=AnyTrue[n*Divisors[n], zQ];
Select[Range[200], fQ] (* zQ defined by T. D. Noe at A083207 *)
CROSSREFS
Supersequence of A083207.
Sequence in context: A373676 A114989 A362012 * A363171 A336323 A175352
KEYWORD
nonn
AUTHOR
Ivan N. Ianakiev, Apr 17 2020
STATUS
approved