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A028196
Expansion of 1/((1-5x)(1-9x)(1-10x)(1-11x)).
1
1, 35, 776, 13930, 221151, 3240825, 44906926, 597218720, 7698198101, 96837355615, 1194615734676, 14505367659510, 173840151316651, 2060770407338405, 24205227062904026, 282088240414000300, 3265447176464616801, 37582206965366853195, 430364865022642734976
OFFSET
0,2
FORMULA
a(n) = 21*a(n-1) - 110*a(n-2) + (9^(n+1) - 5^(n+1))/4, n>=2. - Vincenzo Librandi, Mar 12 2011
a(n) = -5^(n+2)/24 +11^(n+3)/12 -2*10^(n+2) +3^(2*n+6)/8. - R. J. Mathar, Mar 14 2011
MATHEMATICA
CoefficientList[ Series[1/(1 - 35x + 449x^2 - 2485x^3 + 4950x^4), {x, 0, 15}], x] (* Or *)
a[n_] := 21 a[n - 1] - 110 a[n - 2] + (9^(n + 1) - 5^(n + 1))/4; a[0] = 1; a[1] = 35; Array[a, 16, 0] (* Robert G. Wilson v, Mar 14 2011 *)
LinearRecurrence[{35, -449, 2485, -4950}, {1, 35, 776, 13930}, 20] (* Harvey P. Dale, Feb 24 2014 *)
PROG
(Magma) I:=[1, 35, 776, 13930]; [n le 4 select I[n] else 35*Self(n-1)-449*Self(n-2)+2485*Self(n-3)-4950*Self(n-4): n in [1..20]]; // Vincenzo Librandi, Feb 26 2014
CROSSREFS
Sequence in context: A334909 A028213 A028212 * A028208 A028194 A004348
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Feb 26 2014
STATUS
approved