OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..170
Michael De Vlieger, Plot m = a(x) * A002110(y) at (x,y) for m in A002201, smallest 4096 terms m.
EXAMPLE
From Michael De Vlieger, May 14 2018: (Start)
1 2 3 4 5 6 7 ...
+-----------------------------------------------
1 | 2
2 | 6 12
3 | 60 120 360
4 | 2520 5040
5 | 55440
6 | 720720 1441440 4324320
...
(End)
MATHEMATICA
t = Import["b002201.txt", "Data"][[All, -1]]; (* Uses b-file at A002201 Alternatively, use this conversion of terms at A000705 to a 10^4 term dataset for A002201. Processing 10^4 terms will take a long time: *) t = With[{s = Import["b000705.txt", "Data"][[All, -1]]}, FoldList[Times, s]]; f[n_] := With[{d = FactorInteger@ n}, If[n == 1, {0}, ReplacePart[Table[0, {PrimePi[d[[-1, 1]]]}], #] &@ Map[PrimePi@ First@ # -> Last@ # &, d]]]; Union@ Array[Times @@ MapIndexed[Prime[First@#2]^#1 &, #3] & @@ {#1, Boole[First@ #2 > 0] Length@ #2, DeleteCases[-1 + #2, 0] /. -1 -> 0} & @@ {t[[#]], f@ t[[#]]} &, Length@ t]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Apr 09 2018
STATUS
approved