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 A172077 a(n) = n*(n+1)*(7*n^2 - n - 4)/4. 1
 0, 1, 33, 168, 520, 1245, 2541, 4648, 7848, 12465, 18865, 27456, 38688, 53053, 71085, 93360, 120496, 153153, 192033, 237880, 291480, 353661, 425293, 507288, 600600, 706225, 825201, 958608, 1107568, 1273245, 1456845, 1659616, 1882848, 2127873 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The sequence is related to A172076 by a(n) = n*A172076(n) - Sum_{i=0..n-1} A172076(i). This is the case d=7 in the identity n^2*(n+1)*(2*d*n-2*d+3)/6 - Sum_{k=0..n-1} k*(k+1)*(2*d*k-2*d+3)/6 = n*(n+1)*(3*d*n^2 - d*n + 4*n - 2*d + 2)/12. - Bruno Berselli, Apr 21 2010 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 B. Berselli, A description of the recursive method in Comments lines: website Matem@ticamente (in Italian). Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1). FORMULA G.f.: x*(1 + 28*x + 13*x^2)/(1-x)^5. - R. J. Mathar, Nov 17 2011 E.g.f.: x*(4 + 62*x + 48*x^2 + 7*x^3)*exp(x)/4. - G. C. Greubel, Aug 30 2019 MAPLE seq(n*(n+1)*(7*n^2-n-4)/4, n=0..40); # G. C. Greubel, Aug 30 2019 MATHEMATICA CoefficientList[Series[x(1 +28x +13x^2)/(1-x)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Jan 01 2014 *) Table[n*(n+1)*(7*n^2-n-4)/4, {n, 0, 40}] (* G. C. Greubel, Aug 30 2019 *) PROG (Magma) [n*(n+1)*(7*n^2-n-4)/4: n in [0..40]]; // Vincenzo Librandi, Jan 01 2014 (PARI) vector(40, n, n*(n-1)*(7*(n-1)^2-(n-1)-4)/4) \\ G. C. Greubel, Aug 30 2019 (Sage) [n*(n+1)*(7*n^2-n-4)/4 for n in (0..40)] # G. C. Greubel, Aug 30 2019 (GAP) List([0..40], n-> n*(n+1)*(7*n^2-n-4)/4); # G. C. Greubel, Aug 30 2019 CROSSREFS Cf. A172076. Sequence in context: A233064 A183776 A256021 * A180943 A113752 A155883 Adjacent sequences: A172074 A172075 A172076 * A172078 A172079 A172080 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Jan 25 2010 STATUS approved

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Last modified December 6 16:00 EST 2022. Contains 358644 sequences. (Running on oeis4.)