cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A334166 Numbers k having a divisor d, such that d*k is a Zumkeller number (A083207).

Original entry on oeis.org

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

Views

Author

Ivan N. Ianakiev, Apr 17 2020

Keywords

Comments

Conjecture: The difference between two consecutive terms is 6 at most.

Examples

			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.
		

Crossrefs

Supersequence of A083207.

Programs

  • 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 *)