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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 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 A260663 A241857 Adjacent sequences:  A127752 A127753 A127754 * A127756 A127757 A127758 KEYWORD sign,tabl AUTHOR Paul Barry, Jan 28 2007 STATUS approved

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