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A074081 Sum of determinants of 3rd order principal minors of powers of inverse of tetramatrix ((1,1,0,0),(1,0,1,0),(1,0,0,1),(1,0,0,0)). 3
4, -1, 3, -7, 15, -26, 51, -99, 191, -367, 708, -1365, 2631, -5071, 9775, -18842, 36319, -70007, 134943, -260111, 501380, -966441, 1862875, -3590807, 6921503, -13341626, 25716811, -49570747, 95550687, -184179871, 355018116, -684319421, 1319068095, -2542585503, 4900991135 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

a(n)=(-1)^nT(n), where T(n) are the generalized tetranacci numbers A073817

LINKS

Table of n, a(n) for n=0..34.

Index entries for linear recurrences with constant coefficients, signature (-1,1,-1,1).

FORMULA

a(n)=-a(n-1)+a(n-2)-a(n-3)+a(n-4), a(0)=4, a(1)=-1, a(2)=3, a(3)=-7. G.f.: (4+3x-2x^2+x^3)/(1+x-x^2+x^3-x^4).

MATHEMATICA

CoefficientList[Series[4+3*x-2*x^2+x^3)/(1+x-x^2+x^3-x^4), {x, 0, 40}], x]

CROSSREFS

Sequence in context: A109531 A200132 A073817 * A132703 A176217 A226574

Adjacent sequences:  A074078 A074079 A074080 * A074082 A074083 A074084

KEYWORD

easy,sign

AUTHOR

Mario Catalani (mario.catalani(AT)unito.it), Aug 19 2002

STATUS

approved

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Last modified September 22 16:41 EDT 2019. Contains 327311 sequences. (Running on oeis4.)