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 A127710 Inverse of the triangle A(n,k)=if(k<=n,if(n<=2k,1/(n+1),0),0). 0

%I #2 Mar 30 2012 18:59:19

%S 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,

%T 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

%N Inverse of the triangle A(n,k)=if(k<=n,if(n<=2k,1/(n+1),0),0).

%C It is conjectured that all elements of this triangle are integers. It appears that the row sums are the ruler function A001511.

%e Triangle begins

%e 1,

%e 0, 2,

%e 0, -2, 3,

%e 0, 2, -3, 4,

%e 0, 0, 0, -4, 5,

%e 0, -2, 3, 0, -5, 6,

%e 0, 0, 0, 0, 0, -6, 7,

%e 0, 2, -3, 4, 0, 0, -7, 8,

%e 0, 0, 0, 0, 0, 0, 0, -8, 9,

%e 0, 0, 0, -4, 5, 0, 0, 0, -9, 10,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, -10, 11,

%e 0, -2, 3, 0, -5, 6, 0, 0, 0, 0, -11, 12,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -12, 13

%e Triangle is the inverse of the triangle

%e 1,

%e 0, 1/2,

%e 0, 1/3, 1/3,

%e 0, 0, 1/4, 1/4,

%e 0, 0, 1/5, 1/5, 1/5,

%e 0, 0, 0, 1/6, 1/6, 1/6,

%e 0, 0, 0, 1/7, 1/7, 1/7, 1/7,

%e 0, 0, 0, 0, 1/8, 1/8, 1/8, 1/8,

%e 0, 0, 0, 0, 1/9, 1/9, 1/9, 1/9, 1/9,

%e 0, 0, 0, 0, 0, 1/10, 1/10, 1/10, 1/10, 1/10,

%e 0, 0, 0, 0, 0, 1/11, 1/11, 1/11, 1/11, 1/11, 1/11

%K sign,tabl

%O 0,3

%A _Paul Barry_, Jan 24 2007

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Last modified October 4 17:22 EDT 2023. Contains 365887 sequences. (Running on oeis4.)