OFFSET
2,1
COMMENTS
The row n has length A001221(n) iff n is squarefree or a perfect power.
EXAMPLE
The triangle begins:
2;
3;
2;
5;
2, 3;
7;
2;
3;
2, 5;
11;
2;
13;
2, 7;
3, 5;
...
The 12th row consists of {2} because 12 = 2*2*3, and the prime factor with the highest multiplicity is 2.
The 30th row consists of {2, 3, 5} because 30 = 2*3*5, and the prime factors with the highest multiplicity are 2, 3, and 5.
MATHEMATICA
r[n_]:=Commonest[Flatten[Table[#[[1]], {#[[2]]}] & /@ FactorInteger[n]]]; Flatten[Array[r, 58, 2]]
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Stefano Spezia, Mar 19 2023
STATUS
approved