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 A239449 7*n^2 - 5*n + 1. 3
 1, 3, 19, 49, 93, 151, 223, 309, 409, 523, 651, 793, 949, 1119, 1303, 1501, 1713, 1939, 2179, 2433, 2701, 2983, 3279, 3589, 3913, 4251, 4603, 4969, 5349, 5743, 6151, 6573, 7009, 7459, 7923, 8401, 8893, 9399, 9919, 10453, 11001, 11563, 12139, 12729, 13333 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(n) = A239426(n) / A003215(n-1). LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA G.f.: ( -1-13*x^2 ) / (x-1)^3 . - R. J. Mathar, Mar 31 2014 MATHEMATICA CoefficientList[Series[(1 + 13 x^2)/(1 - x)^3, {x, 0, 50}], x] (* Vincenzo Librandi, Apr 02 2014 *) PROG (Haskell) a239449 n = (7 * n - 5) * n + 1 (MAGMA) [7*n^2-5*n+1: n in [0..50]]; // Vincenzo Librandi, Apr 02 2014 (PARI) a(n)=7*n^2-5*n+1 \\ Charles R Greathouse IV, Jun 17 2017 CROSSREFS Sequence in context: A023280 A054697 A214883 * A112627 A222185 A265774 Adjacent sequences:  A239446 A239447 A239448 * A239450 A239451 A239452 KEYWORD nonn,easy AUTHOR Reinhard Zumkeller, Mar 19 2014 STATUS approved

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Last modified April 21 23:52 EDT 2021. Contains 343156 sequences. (Running on oeis4.)