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A140147
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a(1)=1, a(n)=a(n-1)+n^1 if n odd, a(n)=a(n-1)+ n^5 if n is even.
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1
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1, 33, 36, 1060, 1065, 8841, 8848, 41616, 41625, 141625, 141636, 390468, 390481, 928305, 928320, 1976896, 1976913, 3866481, 3866500, 7066500, 7066521, 12220153, 12220176, 20182800, 20182825, 32064201, 32064228, 49274596, 49274625
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| a(n)=a(n-1)+{[1-(-1)^n]/2}*n+{[1+(-1)^n]/2}*n^5, with a(1)=1 a(n)=-(1/4)*(-1)^n*n-(5/8)*(-1)^n*n^2+(5/24)*n^2+(1/4)*n+(1/12)*n^6+(1/4)*(-1)^n*n^5+(1/4)*n^5+(5/8) *(-1)^n*n^4+(5/24)*n^4, with n>=1 - Paolo P. Lava (paoloplava(AT)gmail.com), Jun 06 2008
G.f.: -x*(1+32*x-3*x^2+832*x^3+2*x^4+2112*x^5+2*x^6+832*x^7-3*x^8+32*x^9+x^10)/ ((1+x)^6*(x-1)^7). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 22 2009]
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MATHEMATICA
| a = {}; r = 1; s = 5; 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*)
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CROSSREFS
| Cf. A000027, A000217, A000330, A000537, A000538, A000539, A136047, A140113.
Sequence in context: A144425 A180329 A020260 * A083883 A039326 A043149
Adjacent sequences: A140144 A140145 A140146 * A140148 A140149 A140150
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KEYWORD
| nonn
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AUTHOR
| Jasinski Artur (grafix(AT)csl.pl), May 12 2008
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