%I #6 May 17 2018 21:36:25
%S 3,4,6,18,450,205439850,241382525361273331926149714645357743772646450
%N A prime-multiplicity (or run-length) describing recurrence: a(n+1) = A181821(a(n)).
%C The first entry 3 is optional so has offset 0.
%e The list of multisets with Heinz numbers in the sequence is A014643. The number of k's in row n + 1 is equal to the k-th term of row n. The length of row n is A014644(n).
%e 3: {2}
%e 4: {1,1}
%e 6: {1,2}
%e 18: {1,2,2}
%e 450: {1,2,2,3,3}
%e 205439850: {1,2,2,3,3,4,4,4,5,5,5}
%t Function[m,Times@@Prime/@m]/@NestList[Join@@Table[Table[i,{#[[i]]}],{i,Length[#]}]&,{2},6]
%Y Cf. A001462, A014643, A014644, A055932, A056239, A112798, A130091, A181819, A181821, A182850-A182858, A296150, A275870, A304455, A304678.
%K nonn
%O 0,1
%A _Gus Wiseman_, May 16 2018