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 A163979 a(n) = n*(n-1) + A144437(n+2). 1
 1, 3, 5, 7, 15, 23, 31, 45, 59, 73, 93, 113, 133, 159, 185, 211, 243, 275, 307, 345, 383, 421, 465, 509, 553, 603, 653, 703, 759, 815, 871, 933, 995, 1057, 1125, 1193, 1261, 1335, 1409, 1483, 1563, 1643, 1723, 1809, 1895, 1981, 2073, 2165, 2257, 2355, 2453, 2551 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS First differences are 2, 2, 2, 8, 8, 8, 14, 14, 14, 20, 20, 20,... (triplicated A016933). LINKS G. C. Greubel, Table of n, a(n) for n = 0..5000 Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-2,1). FORMULA a(n) = A002378(n-1) + A144437(n+2). a(n) = 2*a(n-1) - a(n-2) + a(n-3) - 2*a(n-4) + a(n-5). G.f.: (1 +x -x^3 +5*x^4)/( (1 +x +x^2)*(1 -x)^3 ). E.g.f.: (1/3)*((7+3*x^2)*exp(x) - 4*exp(-x/2)*cos(sqrt(3)*x/2)). - G. C. Greubel, Aug 24 2017 MATHEMATICA LinearRecurrence[{2, -1, 1, -2, 1}, {1, 3, 5, 7, 15}, 60]  (* or *) CoefficientList[ Series[-(1+x+5x^4-x^3)/((1+x+x^2)(x-1)^3), {x, 0, 60}], x]  (* Harvey P. Dale, Apr 20 2011 *) PROG (PARI) x='x+O('x^50); Vec((1+x-x^3+5*x^4)/((1+x+x^2)*(1-x)^3)) \\ G. C. Greubel, Aug 24 2017 CROSSREFS Sequence in context: A057743 A071169 A172235 * A124248 A029514 A061950 Adjacent sequences:  A163976 A163977 A163978 * A163980 A163981 A163982 KEYWORD nonn,easy AUTHOR Paul Curtz, Aug 07 2009 EXTENSIONS Edited and extended by R. J. Mathar, Aug 12 2009 STATUS approved

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Last modified February 18 20:25 EST 2019. Contains 320262 sequences. (Running on oeis4.)