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 A000803 a(n+3) = a(n+2) + a(n+1) + a(n) - 4. (Formerly M4472 N2232) 3
 0, 0, 8, 4, 8, 16, 24, 44, 80, 144, 264, 484, 888, 1632, 3000, 5516, 10144, 18656, 34312, 63108, 116072, 213488, 392664, 722220, 1328368, 2443248, 4493832, 8265444, 15202520, 27961792, 51429752, 94594060, 173985600, 320009408 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS This sequence and A004306 coincide from the term "24" onwards. This follows easily by studying the two g.f.'s. - R. J. Mathar and Andrew S. Plewe, Dec 04 2007 REFERENCES N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n = 0..400 Henry Beker and Chris Mitchell, Permutations with restricted displacement, SIAM J. Algebraic Discrete Methods 8 (1987), no. 3, 338--363. MR0897734 (89f:05009). N. Metropolis, M. L. Stein, P. R. Stein, Permanents of cyclic (0,1) matrices, J. Combin. Theory, 7 (1969), 291-321. H. Minc, Permanents of (0,1)-circulants, Canad. Math. Bull., 7 (1964), 253-263. Index entries for linear recurrences with constant coefficients, signature (2,0,0,-1). FORMULA G.f.: -4x^2*(3x-2) /((x-1)(x^3+x^2+x-1)) = 2(-5x^2+1)/(x^3+x^2+x-1)-2/(x-1). - R. J. Mathar, Dec 04 2007 a(0)=0, a(1)=0, a(2)=8, a(3)=4, a(n) = 2*a(n-1) - a(n-4). - Harvey P. Dale, Mar 25 2013 MATHEMATICA LinearRecurrence[{2, 0, 0, -1}, {0, 0, 8, 4}, 40] (* Harvey P. Dale, Mar 25 2013 *) PROG (Haskell) a000803 n = a000803_list !! n a000803_list = 0 : 0 : 8 : zipWith (+)                (tail \$ zipWith (+) (tail a000803_list) a000803_list)                (map (subtract 4) a000803_list) -- Reinhard Zumkeller, Nov 18 2011 (PARI) concat([0, 0], Vec((8-12*x)/(1-2*x+x^4)+O(x^97))) \\ Charles R Greathouse IV, Nov 18 2011 CROSSREFS Cf. A000804, A000805, A004306. Sequence in context: A087015 A200224 A124012 * A198063 A323736 A093208 Adjacent sequences:  A000800 A000801 A000802 * A000804 A000805 A000806 KEYWORD nonn,easy,nice AUTHOR EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org), Mar 17 2000 STATUS approved

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Last modified November 20 23:06 EST 2019. Contains 329348 sequences. (Running on oeis4.)