OFFSET
1,1
COMMENTS
EXAMPLE
This is a list of normalized factorizations (see A112798) of selected entries:
8: {1,1,1}
30: {1,2,3}
360: {1,1,1,2,2,3}
720: {1,1,1,1,2,2,3}
900: {1,1,2,2,3,3}
1440: {1,1,1,1,1,2,2,3}
2160: {1,1,1,1,2,2,2,3}
2880: {1,1,1,1,1,1,2,2,3}
4320: {1,1,1,1,1,2,2,2,3}
5760: {1,1,1,1,1,1,1,2,2,3}
8640: {1,1,1,1,1,1,2,2,2,3}
Starting with A112798(1801800) and repeatedly taking the multiset of multiplicities we have {1,1,1,2,2,3,3,4,5,6} -> {1,1,1,2,2,3} -> {1,2,3} -> {1,1,1} -> {3}, so 1801800 belongs to the sequence.
MATHEMATICA
Join@@Position[Table[Switch[n, 1, 0, _?PrimeQ, 1, _, NestWhile[Sort[Length/@Split[#]]&, Sort[Last/@FactorInteger[n]], Length[#]>1&]//First], {n, 200}], 3]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 15 2018
STATUS
approved