A127767 - OEIS

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A127767

Inverse of number triangle A(n,k)=if(k<=n,if(n<=2k,1/C(n),0),0), C(n)=A000108(n).

1, 0, 1, 0, -1, 2, 0, 1, -2, 5, 0, 0, 0, -5, 14, 0, -1, 2, 0, -14, 42, 0, 0, 0, 0, 0, -42, 132, 0, 1, -2, 5, 0, 0, -132, 429, 0, 0, 0, 0, 0, 0, 0, -429, 1430, 0, 0, 0, -5, 14, 0, 0, 0, -1430, 4862, 0, 0, 0, 0, 0, 0, 0, 0, 0, -4862, 16796 (list; table; graph; refs; listen; history; text; internal format)

	OFFSET	`0,6`
	COMMENTS	`It is conjectured that all elements of the triangle are integers. Row sums give A127768.`
	LINKS	`Table of n, a(n) for n=0..65.`
	EXAMPLE	`Triangle begins` `1,` `0, 1,` `0, -1, 2,` `0, 1, -2, 5,` `0, 0, 0, -5, 14,` `0, -1, 2, 0, -14, 42,` `0, 0, 0, 0, 0, -42, 132,` `0, 1, -2, 5, 0, 0, -132, 429,` `0, 0, 0, 0, 0, 0, 0, -429, 1430,` `0, 0, 0, -5, 14, 0, 0, 0, -1430, 4862,` `0, 0, 0, 0, 0, 0, 0, 0, 0, -4862, 16796` `Inverse of triangle` `1,` `0, 1,` `0, 1/2, 1/2,` `0, 0, 1/5, 1/5,` `0, 0, 1/14, 1/14, 1/14,` `0, 0, 0, 1/42, 1/42, 1/42,` `0, 0, 0, 1/132, 1/132, 1/132, 1/132,` `0, 0, 0, 0, 1/429, 1/429, 1/429, 1/429,` `0, 0, 0, 0, 1/1430, 1/1430, 1/1430, 1/1430, 1/1430,` `0, 0, 0, 0, 0, 1/4862, 1/4862, 1/4862, 1/4862, 1/4862,` `0, 0, 0, 0, 0, 1/16796, 1/16796, 1/16796, 1/16796, 1/16796, 1/16796`
	CROSSREFS	`Sequence in context: A071502 A074704 A025247 * A055509 A006667 A112570` `Adjacent sequences: A127764 A127765 A127766 * A127768 A127769 A127770`
	KEYWORD	`sign,tabl`
	AUTHOR	`Paul Barry, Jan 28 2007`
	STATUS	`approved`

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Last modified May 19 02:47 EDT 2013. Contains 225428 sequences.