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A115634
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Expansion of (1-4*x^2)/(1-x^2).
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3
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1, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0, -3, 0
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OFFSET
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0,3
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COMMENTS
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Row sums of number triangle A115633.
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LINKS
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FORMULA
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a(n) = 4*0^n - 3*(1 + (-1)^n)/2.
a(n) = 1 if n = 0, otherwise a(n) = -A010674(n-1).
E.g.f.: 4 - 3*cosh(x). (End)
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MATHEMATICA
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Join[{1}, -3*Mod[Range[100] -1, 2]] (* G. C. Greubel, Nov 23 2021 *)
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PROG
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(Magma) [4*0^n -3*(1+(-1)^n)/2: n in [0..100]]; // G. C. Greubel, Nov 23 2021
(Sage) [1]+[-3*((n-1)%2) for n in (1..100)] # G. C. Greubel, Nov 23 2021
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CROSSREFS
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KEYWORD
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easy,sign
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AUTHOR
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STATUS
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approved
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