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A075495
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a(n)=Sum((-1)^(i+Floor(n/2))S(2i+e),(i=0,..,Floor(n/2))), where S(n) are inverted tribonacci numbers (A075298).
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0
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1, 1, -6, 4, 7, -15, 8, 12, -31, 29, 10, -72, 95, -11, -160, 264, -111, -311, 682, -484, -505, 1673, -1656, -524, 3857, -4987, 602, 8240, -13825, 6189, 15872, -35888, 26209, 25553, -87654, 88308, 24903, -200863, 264264, -38500, -426623, 729389, -341270, -814744, 1885407, -1411931, -1288224
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| a(n) is the convolution of S(n) with the sequence (1,0,-1,0,1,0,-1,0,....) A056594.
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FORMULA
| a(n)=-a(n-1)-2a(n-2)-a(n-4)+a(n-5), a(0)=1, a(1)=1, a(2)=-6, a(3)=4, a(4)=7. Ogf (1+2x-3x^2)/(1+x+2x^2+x^4-x^5).
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MATHEMATICA
| CoefficientList[Series[(1 + 2x - 3x^2)/(1 + x + 2x^2 + x^4 - x^5), {x, 0, 50}], x]
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CROSSREFS
| Cf. A075298, A075419, A056594.
Sequence in context: A153306 A092160 A118289 * A070652 A195487 A073746
Adjacent sequences: A075492 A075493 A075494 * A075496 A075497 A075498
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KEYWORD
| easy,sign
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AUTHOR
| Mario Catalani (mario.catalani(AT)unito.it), Sep 19 2002
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