A081915 a(n) = 4^n*(n^3 - 3n^2 + 2n + 384)/384.
1, 4, 16, 65, 272, 1184, 5376, 25344, 122880, 606208, 3014656, 15007744, 74448896, 367001600, 1795162112, 8707375104, 41875931136, 199715979264, 944892805120, 4436701216768, 20684562497536, 95794950569984, 440904162738176
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..150
- Index entries for linear recurrences with constant coefficients, signature (16,-96,256,-256)
Crossrefs
Cf. A081916.
Programs
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Magma
[4^n*(n^3-3*n^2+2*n+384)/384: n in [0..40]]; // Vincenzo Librandi, Apr 27 2011
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Mathematica
LinearRecurrence[{16,-96,256,-256},{1,4,16,65},30] (* Harvey P. Dale, Aug 14 2017 *) CoefficientList[Series[(1 - 12x + 48x^2 - 63x^3)/(1-4x)^4 ,{x, 0, 30}], x] (* Stefano Spezia, Sep 02 2018 *)
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PARI
a(n)=4^n*(n^3-3*n^2+2*n+384)/384 \\ Charles R Greathouse IV, Oct 07 2015
Formula
a(n) = 4^n*(n^3 - 3n^2 + 2n + 384)/384.
G.f.: (1 - 12x + 48x^2 - 63x^3)/(1-4x)^4.
Comments