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 A000338 Expansion of (5-2x)(1-x^3)/(1-x)^4. (Formerly M3877 N1589) 3
 5, 18, 42, 75, 117, 168, 228, 297, 375, 462, 558, 663, 777, 900, 1032, 1173, 1323, 1482, 1650, 1827, 2013, 2208, 2412, 2625, 2847, 3078, 3318, 3567, 3825, 4092, 4368, 4653, 4947, 5250, 5562, 5883, 6213, 6552, 6900, 7257, 7623, 7998, 8382, 8775, 9177, 9588, 10008, 10437, 10875, 11322, 11778 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 REFERENCES J. Riordan, Discordant permutations, Scripta Math., 20 (1954), 14-23. 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 = 3..1000 Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992. Simon Plouffe, 1031 Generating Functions and Conjectures, Université du Québec à Montréal, 1992. J. Riordan, Discordant permutations, Scripta Math., 20 (1954), 14-23. [Annotated scanned copy] Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = (9/2)*n^2 - (15/2)*n, n>2. - Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Feb 17 2001 MAPLE ff := n->9/2*n^2-15/2*n; seq(ff(n), n=3..60); # Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Feb 17 2001 A000338:=(2*z-5)*(z**2+z+1)/(z-1)**3; # conjectured by Simon Plouffe in his 1992 dissertation MATHEMATICA nn = 100; CoefficientList[Series[(5 - 2 x) (1 - x^3)/(1 - x)^4, {x, 0, nn}], x] (* T. D. Noe, Jun 19 2012 *) LinearRecurrence[{3, -3, 1}, {5, 18, 42, 75}, 60] (* Harvey P. Dale, Sep 20 2016 *) CROSSREFS Sequence in context: A225272 A276819 A236364 * A212343 A056640 A272703 Adjacent sequences:  A000335 A000336 A000337 * A000339 A000340 A000341 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Feb 17 2001 STATUS approved

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Last modified December 10 17:41 EST 2018. Contains 318049 sequences. (Running on oeis4.)