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A016250
Expansion of 1/((1-x)(1-7x)(1-9x)).
1
1, 17, 210, 2290, 23411, 230307, 2210020, 20850980, 194384421, 1796538997, 16498405430, 150792530070, 1373280939031, 12472565630087, 113044350922440, 1022937980063560, 9245213572903241, 83478324422447577, 753204735666257050, 6792141332045915450
OFFSET
0,2
FORMULA
a(0)=1, a(1)=17, a(n) = 16*a(n-1) - 63*a(n-2) + 1. - Vincenzo Librandi, Feb 10 2011
a(n) = (3*9^(n+2) - 4*7^(n+2) + 1)/48. - Yahia Kahloune, Jul 09 2013
a(n) = 17*a(n-1) - 79*a(n-2) + 63*a(n-3) for n > 2. - Colin Barker, Sep 01 2015
MATHEMATICA
CoefficientList[Series[1/((1-x)(1-7x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[ {17, -79, 63}, {1, 17, 210}, 30] (* Harvey P. Dale, Apr 21 2020 *)
PROG
(PARI) Vec(-1/((x-1)*(7*x-1)*(9*x-1)) + O(x^30)) \\ Colin Barker, Sep 01 2015
CROSSREFS
Sequence in context: A014921 A081035 A016299 * A255819 A070137 A021054
KEYWORD
nonn,easy
STATUS
approved