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A117378
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Expansion of (1-4x)/(1-x+x^2).
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5
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1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1, -3, -4, -1, 3, 4, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Row sums of number triangle A117377.
Periodic sequence with period {1, -3, -4, -1, 3, 4}. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 03 2008]
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LINKS
| Index entries for sequences related to linear recurrences with constant coefficients
Tanya Khovanova, Recursive Sequences
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FORMULA
| a(n)=sum{k=0..n, (-1)^(n-k)(C(k,n-k)+4*C(k, n-k-1))}
a(n)=(1/6)*{3*(n mod 6)-[(n+1) mod 6)]-4*[(n+2) mod 6)]-3*[(n+3) mod 6)]+[(n+4) mod 6)]+4*[(n+5) mod 6)]}, with n>=0 - Paolo P. Lava (paoloplava(AT)gmail.com), Feb 01 2008
a(n)=a(n-1)-a(n-2) ; a(0)=1, a(1)=-3. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 03 2008]
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MATHEMATICA
| CoefficientList[Series[(1 - 4 x)/(1 - x + x^2), {x, 0, 200}], x] (* From Vladimir Joseph Stephan Orlovsky, Jun 11 2011 *)
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CROSSREFS
| Sequence in context: A124909 A090279 A101667 * A088197 A087517 A128529
Adjacent sequences: A117375 A117376 A117377 * A117379 A117380 A117381
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KEYWORD
| easy,sign
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Mar 10 2006
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