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.
%I A339980 #4 Dec 25 2020 19:32:31
%S A339980 36,72,180,200,252,360,392,396,468,504,600,612,684,784,792,828,936,
%T A339980 1044,1116,1176,1224,1260,1332,1368,1400,1476,1548,1656,1692,1908,
%U A339980 1936,1960,1980,2088,2124,2196,2200,2232,2340,2352,2412,2520,2556,2600,2628,2664,2704
%N A339980 Coreful Zumkeller numbers (A339979) whose set of coreful divisors can be partitioned into two disjoint sets of equal sum in a single way.
%C A339980 A coreful divisor d of a number k is a divisor with the same set of distinct prime factors as k, or rad(d) = rad(k), where rad(k) is the largest squarefree divisor of k (A007947).
%C A339980 The coreful perfect numbers (A307958) are a subsequence.
%e A339980 36 is a term since there is only one partition of its set of coreful divisors, {6, 12, 18, 36}, into 2 disjoint sets whose sums are equal: 6 + 12 + 18 = 36.
%t A339980 corZumQ[n_] := Module[{r = Times @@ FactorInteger[n][[;; , 1]], d, sum, x}, d = r*Divisors[n/r]; (sum = Plus @@ d) >= 2*n && EvenQ[sum] && CoefficientList[Product[1 + x^i, {i, d}], x][[1 + sum/2]] == 2]; Select[Range[10000], corZumQ]
%Y A339980 A307958 is a subsequence.
%Y A339980 Subsequence of A308053 and A339979.
%Y A339980 Cf. A007947, A057723.
%Y A339980 Similar sequences: A083209, A335143, A335199, A335202, A335217, A335219.
%K A339980 nonn
%O A339980 1,1
%A A339980 _Amiram Eldar_, Dec 25 2020