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A016633
Expansion of 1/((1-2x)(1-11x)(1-12x)).
1
1, 25, 447, 6989, 101759, 1417941, 19180519, 253983853, 3309800367, 42599540357, 542895780791, 6863463633117, 86197420501375, 1076563471968373, 13382900349107463, 165700329729679181
OFFSET
0,2
FORMULA
FromVincenzo Librandi,Oct 09 2011: (Start)
a(n) = (648*12^n + 2^(n+1) - 5*11^(n+2))/45.
a(n) = 23*a(n-1) - 132*a(n-2) + 2^n.
a(n) = 25*a(n-1) - 178*a(n-2) + 264*a(n-3), n >= 3. (End)
MATHEMATICA
CoefficientList[Series[1/((1 - 2 x) (1 - 11 x) (1 - 12 x)), {x, 0, 15}], x] (*Michael De Vlieger,Jan 31 2018 *)
PROG
(Sage) [(12^n - 2^n)/10-(11^n - 2^n)/9 for n in range(2, 18)] #Zerinvary Lajos,Jun 05 2009
(Magma) [(648*12^n +2^(n+1)-5*11^(n+2))/45: n in [0..20]]; //Vincenzo Librandi,Oct 09 2011
(PARI) Vec(1/((1-2*x)*(1-11*x)*(1-12*x))+O(x^99)) \\Charles R Greathouse IV,Sep 26 2012
KEYWORD
nonn,easy
STATUS
approved