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

1,2

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

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

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

Cf. A000142, A002034, A038024, A046021.

Sequence in context: A127562 A096113 A110797 * A121663 A096112 A052330

Adjacent sequences: A083869 A083870 A083871 * A083873 A083874 A083875

Keyword

nonn,tabf,look

Author

Jon Perry, Jun 18 2003

Extensions

Extended by Ray Chandler, Aug 23 2005

Status

approved