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A165680 Triangle of the divisors of the coefficients of triangles A138771 and A165675 4
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 6, 1, 1, 1, 2, 6, 24, 1, 1, 1, 2, 6, 24, 120, 1, 1, 1, 2, 6, 24, 120, 720, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,10

LINKS

Table of n, a(n) for n=1..66.

FORMULA

a(n) = A138771(n)/A165675(n-1).

EXAMPLE

Triangle starts:

1,

1, 1,

1, 1, 1,

1, 1, 1, 2,

1, 1, 1, 2, 6,

1, 1, 1, 2, 6, 24,

1, 1, 1, 2, 6, 24, 120,

1, 1, 1, 2, 6, 24, 120, 720,

1, 1, 1, 2, 6, 24, 120, 720, 5040,

1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320,

1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880,

...

MAPLE

nmax:=11: for n from 1 to nmax do a(n, 1):=1 od: for n from 2 to nmax do for m from 2 to n do a(n, m):=(m-2)! od: od: for n from 1 to nmax do seq(a(n, m), m=1..n) od;

CROSSREFS

Cf. A138771, A165675 and A000142.

A000012 (3x), A007395, A010722, A010863 equal the first six left hand columns.

A159333 equals, for n=>-1, all right hand columns.

A067078 equals the row sums.

Sequence in context: A126886 A179272 A264753 * A248049 A231867 A105685

Adjacent sequences:  A165677 A165678 A165679 * A165681 A165682 A165683

KEYWORD

easy,nonn,tabl

AUTHOR

Johannes W. Meijer, Oct 05 2009

STATUS

approved

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Last modified February 29 08:26 EST 2020. Contains 332355 sequences. (Running on oeis4.)