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A127755 Inverse of number triangle A(n,k)=if(k<=n,if(n<=2k,1/n!,0),0). 1
1, 0, 1, 0, -1, 2, 0, 1, -2, 6, 0, 0, 0, -6, 24, 0, -1, 2, 0, -24, 120, 0, 0, 0, 0, 0, -120, 720, 0, 1, -2, 6, 0, 0, -720, 5040, 0, 0, 0, 0, 0, 0, 0, -5040, 40320, 0, 0, 0, -6, 24, 0, 0, 0, -40320, 362880, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

It is conjectured that this is an integer triangle. Row sums are A127756.

LINKS

Table of n, a(n) for n=0..63.

EXAMPLE

Triangle begins

1,

0, 1,

0, -1, 2,

0, 1, -2, 6,

0, 0, 0, -6, 24,

0, -1, 2, 0, -24, 120,

0, 0, 0, 0, 0, -120, 720,

0, 1, -2, 6, 0, 0, -720, 5040,

0, 0, 0, 0, 0, 0, 0, -5040, 40320,

0, 0, 0, -6, 24, 0, 0, 0, -40320, 362880,

0, 0, 0, 0, 0, 0, 0, 0, 0, -362880, 3628800,

0, -1, 2, 0, -24, 120, 0, 0, 0, 0, -3628800, 39916800,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -39916800, 479001600

Inverse of triangle

1,

0, 1,

0, 1/2, 1/2,

0, 0, 1/6, 1/6,

0, 0, 1/24, 1/24, 1/24,

0, 0, 0, 1/120, 1/120, 1/120,

0, 0, 0, 1/720, 1/720, 1/720, 1/720,

0, 0, 0, 0, 1/5040, 1/5040, 1/5040, 1/5040,

0, 0, 0, 0, 1/40320, 1/40320, 1/40320, 1/40320, 1/40320,

0, 0, 0, 0, 0, 1/362880, 1/362880, 1/362880, 1/362880, 1/362880,

0, 0, 0, 0, 0, 1/3628800, 1/3628800, 1/3628800, 1/3628800, 1/3628800, 1/3628800

CROSSREFS

Sequence in context: A055509 A006667 A112570 * A180662 A241857 A014511

Adjacent sequences:  A127752 A127753 A127754 * A127756 A127757 A127758

KEYWORD

sign,tabl

AUTHOR

Paul Barry, Jan 28 2007

STATUS

approved

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Last modified November 23 09:53 EST 2014. Contains 249840 sequences.