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A262594
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Expansion of (1-2*x)^2/((1-x)^4*(1-4*x)).
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2
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1, 4, 14, 52, 203, 808, 3232, 12936, 51765, 207100, 828466, 3313964, 13255999, 53024192, 212097028, 848388448, 3393554217, 13574217396, 54296870230, 217187481700, 868749927731, 3474999712024, 13899998849384, 55599995399032, 222399981597853, 889599926393388, 3558399705575802, 14233598822305756
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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a(n) = 8*a(n-1)-22*a(n-2)+28*a(n-3)-17*a(n-4)+4*a(n-5) for n>4.
a(n) = (34+2^(7+2*n)+93*n+18*n^2-9*n^3)/162.
(End)
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MATHEMATICA
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CoefficientList[Series[(1-2x)^2/((1-x)^4(1-4x)), {x, 0, 40}], x] (* or *) LinearRecurrence[ {8, -22, 28, -17, 4}, {1, 4, 14, 52, 203}, 40] (* Harvey P. Dale, Jul 04 2022 *)
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PROG
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(PARI) a(n) = (34+2^(7+2*n)+93*n+18*n^2-9*n^3)/162 \\ Colin Barker, Oct 23 2015
(PARI) Vec((1-2*x)^2/((1-x)^4*(1-4*x)) + O(x^40)) \\ Colin Barker, Oct 23 2015
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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