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 A131041 a(n) = 2*a(n-1) - a(n-2) - a(n-4). 3
 1, 1, 1, -1, -4, -8, -13, -17, -17, -9, 12, 50, 105, 169, 221, 223, 120, -152, -645, -1361, -2197, -2881, -2920, -1598, 1921, 8321, 17641, 28559, 37556, 38232, 21267, -24257, -107337, -228649, -371228, -489550, -500535, -282871, 306021 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Generating floretion is .5i' + .5j' + .5k' + .5e + 'ii' (for A131039 it is 'i + .5i' + .5j' + .5k' + .5e and for A131040 it is 1.5i' + .5j' + .5k' + .5e) LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (2, -1, 0, -1). FORMULA G.f. (1-x-2*x^3)/(1-2*x+x^2+x^4) MAPLE Floretion Algebra Multiplication Program, FAMP Code: 2tesseq[.5i' + .5j' + .5k' + .5e + 'ii'] MATHEMATICA LinearRecurrence[{2, -1, 0, -1}, {1, 1, 1, -1}, 40] (* Harvey P. Dale, Oct 14 2012 *) CROSSREFS Cf. A131039, A131040, A131042, A002316, A002531. Sequence in context: A032474 A222304 A103024 * A081843 A004938 A172325 Adjacent sequences:  A131038 A131039 A131040 * A131042 A131043 A131044 KEYWORD easy,sign AUTHOR Creighton Dement, Jun 11 2007 STATUS approved

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