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A123957 G.f.: x^4/( (2*x+1) * (2*x^3+x^2-2*x+1)). 0
0, 0, 0, 1, 0, 3, -4, 5, -24, 19, -76, 133, -208, 627, -852, 2181, -4232, 7443, -18012, 30533, -66880, 133875, -250724, 547013, -1020152, 2108435, -4245612, 8217861, -17089968, 33202291, -67158900, 135095301, -265925992, 541112339, -1069523580, 2146659781, -4309316128, 8553624307 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..38.

Index entries for linear recurrences with constant coefficients, signature (0,3,-4,-4).

FORMULA

a(n)= 3*a(n-2) -4*a(n-3) -4*a(n-4).

a(n)= (-2)^n/32 -9*A077942(n)/32 +10*A077942(n-1)/16 -17*A077942(n-2)/32, n>3. [Mar 28 2010]

MATHEMATICA

M = {{0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}, {-4, -4, 3, 0}}; v[1] = {0, 0, 0, 1}; v[n_] := v[n] = M.v[n - 1]; a1 = Table[v[n][[1]], {n, 1, 50}]

CoefficientList[Series[x^4/((2x+1)(2x^3+x^2-2x+1)), {x, 0, 40}], x] (* or *) LinearRecurrence[{0, 3, -4, -4}, {0, 0, 0, 0, 1}, 40] (* Harvey P. Dale, Dec 27 2015 *)

CROSSREFS

Sequence in context: A116474 A208807 A126896 * A085285 A282250 A254865

Adjacent sequences:  A123954 A123955 A123956 * A123958 A123959 A123960

KEYWORD

sign

AUTHOR

Roger L. Bagula and Gary W. Adamson, Oct 27 2006

EXTENSIONS

Definition replaced with generating function - the Assoc. Eds of the OEIS, Mar 28 2010

STATUS

approved

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Last modified May 19 08:25 EDT 2019. Contains 323389 sequences. (Running on oeis4.)