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Search: id:A140153
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| A140153 |
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a(1)=1, a(n)=a(n-1)+n^3 if n odd, a(n)=a(n-1)+ n^1 if n is even. |
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+0
2
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| 1, 3, 30, 34, 159, 165, 508, 516, 1245, 1255, 2586, 2598, 4795, 4809, 8184, 8200, 13113, 13131, 19990, 20010, 29271, 29293, 41460, 41484, 57109, 57135, 76818, 76846, 101235, 101265, 131056, 131088, 167025, 167059, 209934, 209970, 260623
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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a(n)=a(n-1)+{[1-(-1)^n]/2}*n^3+{[1+(-1)^n]/2}*n, with a(1)=1 a(n)= (-3/16)+(1/4)*(-1)^n*n+(3/16)*(-1)^n-(1/4)*(-1)^n*n^3+(1/4)*n^3-(3/8)*(-1)^n*n^2+(3/8)*n^2+(1/4 )*n+(1/8)*n^4 , with n>=1 - Paolo P. Lava (ppl(AT)spl.at), Jun 06 2008
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MATHEMATICA
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a = {}; r = 3; s = 1; 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
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Cf. A000027, A000217, A000330, A000537, A000538, A000539, A136047, A140113.
Adjacent sequences: A140150 A140151 A140152 this_sequence A140154 A140155 A140156
Sequence in context: A045863 A121023 A124520 this_sequence A095045 A061472 A132084
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KEYWORD
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nonn
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AUTHOR
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Jasinski Artur (grafix(AT)csl.pl), May 12 2008
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