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A075091
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Sum of Lucas numbers and reflected Lucas numbers (comment to A061084).
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2
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4, 0, 6, 0, 14, 0, 36, 0, 94, 0, 246, 0, 644, 0, 1686, 0, 4414, 0, 11556, 0, 30254, 0, 79206, 0, 207364, 0, 542886, 0, 1421294, 0, 3720996, 0, 9741694, 0, 25504086, 0, 66770564, 0, 174807606, 0, 457652254, 0, 1198149156, 0, 3136795214, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| a(n)=((-1)^n+1)L(n), L(n)=Lucas number.
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FORMULA
| a(n)=3a(n-2)-a(n-4), a(0)=4, a(1)=0, a(2)=6, a(3)=0. G.f.: (4-6x^2)/(1-3x^2+x^4).
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MATHEMATICA
| CoefficientList[Series[(4 - 6*x^2)/(1 - 3*x^2 + x^4), {x, 0, 50}], x]
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CROSSREFS
| Cf. A000032, A061084.
Sequence in context: A179939 A163407 A023891 * A132953 A195207 A157721
Adjacent sequences: A075088 A075089 A075090 * A075092 A075093 A075094
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KEYWORD
| easy,nonn
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AUTHOR
| Mario Catalani (mario.catalani(AT)unito.it), Aug 31 2002
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