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A080921
a(n) = 2*a(n-1) + 48*a(n-2), a(0)=0, a(1)=1.
2
0, 1, 2, 52, 200, 2896, 15392, 169792, 1078400, 10306816, 72376832, 639480832, 4753049600, 40201179136, 308548739072, 2546754076672, 19903847628800, 162051890937856, 1279488468058112, 10337467701133312, 82090381869056000
OFFSET
0,3
COMMENTS
Essentially the same as A053455: a(n) = A053455(n-1), n>=1.
FORMULA
a(n) = (8^n - (-6)^n)/14.
a(n) = Sum{k=1..n, binomial(n, 2k-1) * 7^(2(k-1)) }
G.f.: x/((1+6*x)*(1-8*x)).
a(n) = A053455(n-1), n>=1. [R. J. Mathar, Sep 18 2008]
MATHEMATICA
CoefficientList[Series[x / ((1 + 6 x) (1 - 8 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 05 2013 *)
LinearRecurrence[{2, 48}, {0, 1}, 30] (* Harvey P. Dale, Jan 20 2016 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Feb 24 2003
STATUS
approved