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 A316520 #5 Jul 06 2018 17:05:18
%S A316520 3,5,9,10,11,17,21,22,25,27,28,30,31,41,46,57,59,67,68,78,81,82,83,84,
%T A316520 85,88,90,91,98,99,100,105,109,110,111,121,125,127,146,155,157,164,
%U A316520 179,184,191,194,203,208,211,213,222,228,241,243,247,252,253,264,267
%N A316520 Heinz numbers of integer partitions whose average is a prime number.
%C A316520 The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
%e A316520 60 = 2*2*3*5 has prime indices {1,1,2,3} with average 7/4, so 60 does not belong to the sequence.
%e A316520 90 = 2*3*3*5 has prime indices {1,2,2,3} with average 8/2 = 4, so 90 belongs to the sequence.
%t A316520 Select[Range[100],PrimeQ[Mean[If[#==1,{},Flatten[Cases[FactorInteger[#],{p_,k_}:>Table[PrimePi[p],{k}]]]]]]&]
%Y A316520 Cf. A000040, A000041, A000607, A056239, A067538, A078175, A100118, A237984, A296150, A316313, A316413.
%K A316520 nonn
%O A316520 1,1
%A A316520 _Gus Wiseman_, Jul 05 2018