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 A127710 Inverse of the triangle A(n,k)=if(k<=n,if(n<=2k,1/(n+1),0),0). 0
 1, 0, 2, 0, -2, 3, 0, 2, -3, 4, 0, 0, 0, -4, 5, 0, -2, 3, 0, -5, 6, 0, 0, 0, 0, 0, -6, 7, 0, 2, -3, 4, 0, 0, -7, 8, 0, 0, 0, 0, 0, 0, 0, -8, 9, 0, 0, 0, -4, 5, 0, 0, 0, -9, 10, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS It is conjectured that all elements of this triangle are integers. It appears that the row sums are the ruler function A001511. LINKS Table of n, a(n) for n=0..56. EXAMPLE Triangle begins 1, 0, 2, 0, -2, 3, 0, 2, -3, 4, 0, 0, 0, -4, 5, 0, -2, 3, 0, -5, 6, 0, 0, 0, 0, 0, -6, 7, 0, 2, -3, 4, 0, 0, -7, 8, 0, 0, 0, 0, 0, 0, 0, -8, 9, 0, 0, 0, -4, 5, 0, 0, 0, -9, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10, 11, 0, -2, 3, 0, -5, 6, 0, 0, 0, 0, -11, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -12, 13 Triangle is the inverse of the triangle 1, 0, 1/2, 0, 1/3, 1/3, 0, 0, 1/4, 1/4, 0, 0, 1/5, 1/5, 1/5, 0, 0, 0, 1/6, 1/6, 1/6, 0, 0, 0, 1/7, 1/7, 1/7, 1/7, 0, 0, 0, 0, 1/8, 1/8, 1/8, 1/8, 0, 0, 0, 0, 1/9, 1/9, 1/9, 1/9, 1/9, 0, 0, 0, 0, 0, 1/10, 1/10, 1/10, 1/10, 1/10, 0, 0, 0, 0, 0, 1/11, 1/11, 1/11, 1/11, 1/11, 1/11 CROSSREFS Sequence in context: A111565 A299761 A141099 * A137510 A247303 A067871 Adjacent sequences: A127707 A127708 A127709 * A127711 A127712 A127713 KEYWORD sign,tabl AUTHOR Paul Barry, Jan 24 2007 STATUS approved

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Last modified June 6 18:42 EDT 2023. Contains 363150 sequences. (Running on oeis4.)