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A114284
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Riordan array ((1-3x)/(1-x),x).
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2
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1, -2, 1, -2, -2, 1, -2, -2, -2, 1, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 1
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Inverse of A114283. Row sums are 1-2n. Diagonal sums are A114285. Sequence array of 3*0^n-2.
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FORMULA
| T(n, k)=if(k<=n, 3*0^(n-k)-2, 0)
a(n) =-3 floor(1/2 sqrt(8 x+1)-1/2)+3 floor(1/2 sqrt(8 x+9)-1/2)-2 (* From Jackson Xier, Oct 07 2011 *)
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EXAMPLE
| Triangle begins
1;
-2,1;
-2,-2,1;
-2,-2,-2,1;
-2,-2,-2,-2,1;
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MATHEMATICA
| Table[-2 - 3 Floor[1/2 (-1 + Sqrt[1 + 8 x])] +
3 Floor[1/2 (-1 + Sqrt[9 + 8 x])], {x, 0, 250}] (* From Jackson Xier, Oct 07 2011 *)
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CROSSREFS
| Sequence in context: A113189 A143098 A183028 * A023575 A105446 A058978
Adjacent sequences: A114281 A114282 A114283 * A114285 A114286 A114287
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KEYWORD
| easy,sign,tabl
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Nov 20 2005
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