A333232 Terms of A051488 that do not belong to A083207.

5865, 7395, 10005, 15045, 28815, 37995, 45645, 50235, 99705, 134895, 170085, 275655, 310845, 347565, 391935, 436305, 470235, 486795, 521985, 530265, 590295, 613785, 627555, 635205, 658155, 662745, 707115, 791265, 797385, 830415, 835635, 873885, 887655, 979455, 994755

Offset: 1

Author

Ivan N. Ianakiev, Mar 12 2020

Keywords

• nonn

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000
• K. P. S. Bhaskara Rao and Yuejian Peng, On Zumkeller Numbers, Journal of Number Theory, Volume 133, Issue 4, April 2013, pp. 1135-1155.

Crossrefs

Cf. A000010, A051488, A083207.

Programs

Mathematica

(* First 200000 terms of A051488 *)
a051488=Select[Range[200000],EulerPhi[#]T. D. Noe at A083207 *)
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]]; t2=Select[t1,!zQ[#]&]

Extensions

Terms a(12) and beyond from Giovanni Resta, Mar 12 2020