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 A111570 a(n) = a(n-1) + a(n-3) + a(n-4), n >= 4. 5
 2, 5, 4, 7, 14, 23, 34, 55, 92, 149, 238, 385, 626, 1013, 1636, 2647, 4286, 6935, 11218, 18151, 29372, 47525, 76894, 124417, 201314, 325733, 527044, 852775, 1379822, 2232599, 3612418, 5845015, 9457436, 15302453, 24759886 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS See comment and FAMP code for A111569. LINKS FORMULA G.f. (-2-3*x+x^2-x^3)/((1+x^2)*(x^2+x-1)) PROG Floretion Algebra Multiplication Program, FAMP Code: 1vesseq[B+H] with B = - .25'i + .25'j - .25i' + .25j' + k' - .5'kk' - .25'ik' - .25'jk' - .25'ki' - .25'kj' - .5e and H = + .75'ii' + .75'jj' + .75'kk' + .75e CROSSREFS Cf. A001638, A111569, A111571, A111572, A111573, A007598, A000045. Sequence in context: A015948 A119733 A140869 * A057954 A155896 A060710 Adjacent sequences:  A111567 A111568 A111569 * A111571 A111572 A111573 KEYWORD easy,nonn AUTHOR Creighton Dement, Aug 10 2005 STATUS approved

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Last modified January 25 03:49 EST 2020. Contains 331241 sequences. (Running on oeis4.)