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A014904
a(1)=1, a(n) = 20*a(n-1) + n.
3
1, 22, 443, 8864, 177285, 3545706, 70914127, 1418282548, 28365650969, 567313019390, 11346260387811, 226925207756232, 4538504155124653, 90770083102493074, 1815401662049861495, 36308033240997229916, 726160664819944598337, 14523213296398891966758
OFFSET
1,2
FORMULA
From R. J. Mathar, Jul 15 2010: (Start)
G.f.: x/((1-20*x)*(x-1)^2).
a(n) = 22*a(n-1) - 41*a(n-2) + 20*a(n-3). (End)
MATHEMATICA
LinearRecurrence[{22, -41, 20}, {1, 22, 443}, 20] (* Vincenzo Librandi, Oct 20 2012 *)
PROG
(Magma) I:=[1, 22, 443]; [n le 3 select I[n] else 22*Self(n-1) - 41*Self(n-2) + 20*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Oct 20 2012
(Maxima)
a[1]:1$
a[2]:22$
a[3]:443$
a[n]:=22*a[n-1]-41*a[n-2]+20*a[n-3]$
A014904(n):=a[n]$
makelist(A014904(n), n, 1, 30); /* Martin Ettl, Nov 06 2012 */
(PARI) Vec(x/((1-20*x)*(x-1)^2)+O(x^99)) \\ Charles R Greathouse IV, Jul 05 2024
CROSSREFS
Sequence in context: A269540 A095219 A299320 * A353105 A036905 A268460
KEYWORD
nonn,easy
STATUS
approved