A083872 Triangle read by rows in which row n lists first appearance of m such that m divides n!.

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

Author

Jon Perry, Jun 18 2003

Keywords

• nonn
• tabf
• look

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)

Examples

			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
		

Links

• Rémy Sigrist, Rows n = 1..17, flattened

Crossrefs

Cf. A000142, A002034, A038024, A046021.

Programs

Mathematica

lst = {1}; Do[lst = Join[lst, Complement[Divisors[n!], Divisors[(n - 1)!]]], {n, 2, 9}]; lst (* Vladimir Joseph Stephan Orlovsky, Jul 07 2011 *)

Extensions

Extended by Ray Chandler, Aug 23 2005