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 A316904 #5 Jul 17 2018 08:09:41
%S A316904 2,18,72,162,195,250,288,294,390,500,588,648,780,1125,1152,1176,1458,
%T A316904 1560,1755,2000,2250,2352,2592,2646,3120,3185,3510,4000,4500,4608,
%U A316904 4704,4802,5292,6240,6370,6475,7020,8450,9000,9408,10125,10368,10527,10584,12480
%N A316904 Heinz numbers of aperiodic integer partitions into relatively prime parts whose reciprocal sum is an integer.
%C A316904 The reciprocal sum of (y_1, ..., y_k) is 1/y_1 + ... + 1/y_k.
%C A316904 The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
%C A316904 A partition is aperiodic if its multiplicities are relatively prime.
%H A316904 Gus Wiseman, <a href="/A051908/a051908.txt">Sequences counting and ranking integer partitions by their reciprocal sums</a>
%e A316904 The sequence of partitions whose Heinz numbers belong to this sequence begins: (1), (221), (22111), (22221), (632), (3331), (2211111), (4421), (6321), (33311), (44211), (2222111).
%t A316904 Select[Range[2,20000],And[GCD@@FactorInteger[#][[All,2]]==1,GCD@@PrimePi/@FactorInteger[#][[All,1]]==1,IntegerQ[Sum[m[[2]]/PrimePi[m[[1]]],{m,FactorInteger[#]}]]]&]
%Y A316904 Cf. A000837, A002966, A051908, A058360, A100953, A296150, A316854, A316855, A316856, A316857, A316888-A316904.
%K A316904 nonn
%O A316904 1,1
%A A316904 _Gus Wiseman_, Jul 16 2018