

A090665


Triangle read by rows: T(n,k) = number of preferential arrangements of n things beginning with k.


0



1, 2, 1, 6, 5, 2, 26, 25, 18, 6, 150, 149, 134, 84, 241082, 1081, 1050, 870, 480, 120, 9366, 9365, 9302, 8700, 6600, 3240, 720
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OFFSET

0,2


COMMENTS

Rows sums give A000670. The rows are the reverses of the rows of A054255.


LINKS

Table of n, a(n) for n=0..26.


EXAMPLE

1; 2, 1; 6, 5, 2; 26, 25, 18, 6; 150, 149, 134, 84, 24


PROG

The program is written in a variant of APL called J, a product of JSoftware. Since so few people know J, I'll not display the functions used to produce the sequence.


CROSSREFS

Cf. A054255, A008277, A028246.
Sequence in context: A113381 A228175 A118980 * A021826 A159927 A176443
Adjacent sequences: A090662 A090663 A090664 * A090666 A090667 A090668


KEYWORD

nonn,tabl


AUTHOR

Eugene McDonnell (eemcd(AT)mac.com), Dec 16 2003


STATUS

approved



