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A005570
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Number of walks on cubic lattice.
(Formerly M5038)
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2
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17, 50, 99, 164, 245, 342, 455, 584, 729, 890, 1067, 1260, 1469, 1694, 1935, 2192, 2465, 2754, 3059, 3380, 3717, 4070, 4439, 4824, 5225, 5642, 6075, 6524, 6989, 7470, 7967, 8480, 9009, 9554, 10115, 10692, 11285
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OFFSET
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1,1
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COMMENTS
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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FORMULA
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a(n) = 8*n^2 + 9*n.
Sum_{n>=1} 1/a(n) = 80/81 - (sqrt(2)+1)*Pi/18 - log(1+sqrt(2))*sqrt(2)/9 -4*log(2)/9. - Amiram Eldar, Sep 10 2022
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MATHEMATICA
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CoefficientList[Series[(17 - x) / (1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, Nov 05 2014 *)
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PROG
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(PARI) Vec((17-x)/(1-x)^3 + O(x^50)) \\ Michel Marcus, Nov 05 2014
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CROSSREFS
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KEYWORD
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nonn,walk,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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