A127793 - OEIS

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A127793

Inverse of number triangle A(n,k)=if(k<=n,if(n<=2k,1/floor((n+2)/2)),0),0).

1, 0, 1, 0, -1, 2, 0, 1, -2, 2, 0, 0, 0, -2, 3, 0, -1, 2, 0, -3, 3, 0, 0, 0, 0, 0, -3, 4, 0, 1, -2, 2, 0, 0, -4, 4, 0, 0, 0, 0, 0, 0, 0, -4, 5, 0, 0, 0, -2, 3, 0, 0, 0, -5, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, -5, 6 (list; table; graph; refs; listen; history; internal format)

	OFFSET	`0,6`
	COMMENTS	`It is conjectured that the triangle is an integer triangle. The triangle and its inverse both appear to have row sums equal to the all 1's sequence.`
	EXAMPLE	`Triangle begins` `1,` `0, 1,` `0, -1, 2,` `0, 1, -2, 2,` `0, 0, 0, -2, 3,` `0, -1, 2, 0, -3, 3,` `0, 0, 0, 0, 0, -3, 4,` `0, 1, -2, 2, 0, 0, -4, 4,` `0, 0, 0, 0, 0, 0, 0, -4, 5,` `0, 0, 0, -2, 3, 0, 0, 0, -5, 5,` `0, 0, 0, 0, 0, 0, 0, 0, 0, -5, 6,` `0, -1, 2, 0, -3, 3, 0, 0, 0, 0, -6, 6,` `0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -6, 7` `Inverse of the triangle` `1,` `0, 1,` `0, 1/2, 1/2,` `0, 0, 1/2, 1/2,` `0, 0, 1/3, 1/3, 1/3,` `0, 0, 0, 1/3, 1/3, 1/3,` `0, 0, 0, 1/4, 1/4, 1/4, 1/4,` `0, 0, 0, 0, 1/4, 1/4, 1/4, 1/4,` `0, 0, 0, 0, 1/5, 1/5, 1/5, 1/5, 1/5,` `0, 0, 0, 0, 0, 1/5, 1/5, 1/5, 1/5, 1/5, 0;` `0, 0, 0, 0, 0, 1/6, 1/6, 1/6, 1/6, 1/6, 1/6`
	CROSSREFS	`Sequence in context: A131866 A036862 A094238 * A127771 A118407 A101663` `Adjacent sequences: A127790 A127791 A127792 * A127794 A127795 A127796`
	KEYWORD	`sign,tabl`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jan 29 2007`

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Last modified February 17 04:58 EST 2012. Contains 205985 sequences.