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 A135099 a(1)=1, a(n)=a(n-1)+n^5 if n odd, a(n)=a(n-1)+ n^3 if n is even. 1
 1, 9, 252, 316, 3441, 3657, 20464, 20976, 80025, 81025, 242076, 243804, 615097, 617841, 1377216, 1381312, 2801169, 2807001, 5283100, 5291100, 9375201, 9385849, 15822192, 15836016, 25601641, 25619217, 39968124, 39990076, 60501225 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA G.f.: -x*(1+8*x+237*x^2+16*x^3+1682*x^4-48*x^5+1682*x^6+16*x^7+237*x^8+8*x^9+x^ 10)/((1+x)^6*(x-1)^7). [From R. J. Mathar, Feb 22 2009] EXAMPLE a(n)=(3/16)-(3/16)*(-1)^n+(1/4)*(-1)^n*n^3+(1/4)*n^3+(-1)^n*n^2+(1/12)*n^2+(1/12)*n^6-(1/4)*(-1)^n*n^5+(1/4)*n^5-(5/8)*(-1)^n*n^4+(1/3)*n^4, with n>=1 [From Paolo P. Lava, Mar 02 2009] MATHEMATICA a = {}; r = 5; s = 3; Do[k = 0; Do[k = k + (Sin[Pi m/2]^2) m^r + (Cos[Pi m/2]^2) m^s, {m, 1, n}]; AppendTo[a, k], {n, 1, 100}]; a (*Artur Jasinski*) CROSSREFS Cf. A000027, A000217, A000330, A000537, A000538, A000539, A136047, A140113. Sequence in context: A066989 A160501 A075987 * A073427 A194790 A158621 Adjacent sequences:  A135096 A135097 A135098 * A135100 A135101 A135102 KEYWORD nonn AUTHOR Jasinski Artur (grafix(AT)csl.pl), May 12 2008 STATUS approved

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