A195855 a(n) = T(9,n), array T given by A048505.
1, 101, 322, 808, 1872, 4192, 9232, 20144, 43696, 94384, 203184, 436144, 933808, 1994672, 4251568, 9043888, 19201968, 40697776, 86114224, 181927856, 383778736, 808452016, 1700790192, 3573546928, 7499415472, 15720251312
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..2000
- Index entries for linear recurrences with constant coefficients, signature (7,-18,20,-8).
Crossrefs
Programs
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Magma
[(n^2+37*n+324)*2^(n-2)-80: n in [0..30]]
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Mathematica
LinearRecurrence[{7,-18,20,-8},{1,101,322,808},30] (* Harvey P. Dale, Jan 08 2023 *) -
PARI
a(n)=(n^2+37*n+324)<<(n-2)-80 \\ Charles R Greathouse IV, Dec 27 2011
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PARI
Vec((352*x^3-367*x^2+94*x+1)/((x-1)*(2*x-1)^3) + O(x^100)) \\ Colin Barker, Feb 25 2015
Formula
a(n) = (n^2+37*n+324)*2^(n-2)-80.
a(n) = 7*a(n-1)-18*a(n-2)+20*a(n-3)-8*a(n-4). - Colin Barker, Feb 25 2015
G.f.: (352*x^3-367*x^2+94*x+1) / ((x-1)*(2*x-1)^3). Colin Barker, Feb 25 2015