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A083872
Triangle read by rows in which row n lists first appearance of m such that m divides n!.
3
1, 2, 3, 6, 4, 8, 12, 24, 5, 10, 15, 20, 30, 40, 60, 120, 9, 16, 18, 36, 45, 48, 72, 80, 90, 144, 180, 240, 360, 720, 7, 14, 21, 28, 35, 42, 56, 63, 70, 84, 105, 112, 126, 140, 168, 210, 252, 280, 315, 336, 420, 504, 560, 630, 840, 1008, 1260, 1680, 2520, 5040, 32, 64
OFFSET
1,2
COMMENTS
Differs from A110797 starting at a(17)=9.
From Rémy Sigrist, Sep 17 2017: (Start)
Each number k > 0 appears exactly once in the triangle, on row A002034(k).
The n-th row of the triangle:
- contains A038024(n) terms,
- starts with A046021(n),
- ends with n! = A000142(n).
(End)
LINKS
EXAMPLE
1!:1
2!:1,2 -> 2 as 1 has already appeared
3!:1,2,3,6 -> 3,6
4!:1,2,3,4,6,8,12,24 -> 4,8,12,24
MATHEMATICA
lst = {1}; Do[lst = Join[lst, Complement[Divisors[n!], Divisors[(n - 1)!]]], {n, 2, 9}]; lst (* Vladimir Joseph Stephan Orlovsky, Jul 07 2011 *)
CROSSREFS
KEYWORD
nonn,tabf,look
AUTHOR
Jon Perry, Jun 18 2003
EXTENSIONS
Extended by Ray Chandler, Aug 23 2005
STATUS
approved