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 A109803 Expansion of (x^2+1)*(x+1)^2 / ((x-1)*(x^2+x+1)*(x^2+2*x-1)). 1
 1, 4, 11, 29, 72, 175, 425, 1028, 2483, 5997, 14480, 34959, 84401, 203764, 491931, 1187629, 2867192, 6922015, 16711225, 40344468, 97400163, 235144797, 567689760, 1370524319, 3308738401, 7988001124, 19284740651, 46557482429, 112399705512 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Colin Barker, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (2,1,1,-2,-1). FORMULA a(n) = 2*a(n-1) + a(n-2) + a(n-3) - 2*a(n-4) - a(n-5) for n>4. - Colin Barker, May 16 2019 21*a(n) = 12*( A000129(n)+4*A000129(n+1)) -4*7 +b(n)  where b(n>=0) = A049347(n)+5*A049347(n-1) =  1,4,-5,1,4,-5,... periodic with period 3. - R. J. Mathar, Sep 11 2019 MATHEMATICA LinearRecurrence[{2, 1, 1, -2, -1}, {1, 4, 11, 29, 72}, 40] (* Harvey P. Dale, May 11 2020 *) PROG Floretion Algebra Multiplication Program, FAMP Code: 2tessumseq[C*H] with C = - .5'j + .5'k - .5j' + .5k' - 'ii' - .5'ij' - .5'ik' - .5'ji' - .5'ki' and H = + .5'j + .5j', sumtype: (Y[sqa.Findk()], *, sum) (internal program code) (PARI) Vec((1 + x)^2*(1 + x^2) / ((1 - x)*(1 + x + x^2)*(1 - 2*x - x^2)) + O(x^35)) \\ Colin Barker, May 16 2019 CROSSREFS Sequence in context: A062432 A220018 A131046 * A262280 A027968 A027970 Adjacent sequences:  A109800 A109801 A109802 * A109804 A109805 A109806 KEYWORD easy,nonn AUTHOR Creighton Dement, Aug 15 2005 STATUS approved

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Last modified September 28 02:44 EDT 2020. Contains 337392 sequences. (Running on oeis4.)