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A145978
Expansion of 1/(1-x*(1-8*x)).
7
1, 1, -7, -15, 41, 161, -167, -1455, -119, 11521, 12473, -79695, -179479, 458081, 1893913, -1770735, -16922039, -2756159, 132620153, 154669425, -906291799, -2143647199, 5106687193, 22255864785, -18597632759, -196644551039, -47863488967, 1525292919345
OFFSET
0,3
COMMENTS
Row sums of Riordan array (1,1(1-8x)).
FORMULA
a(n) = a(n-1) - 8*a(n-2), a(0)=1, a(1)=1.
a(n) = Sum_{k=0..n} A109466(n,k)*8^(n-k).
MATHEMATICA
LinearRecurrence[{1, -8}, {1, 1}, 50] (* G. C. Greubel, Jan 29 2016 *)
PROG
(Sage) [lucas_number1(n, 1, 8) for n in range(1, 27)] # Zerinvary Lajos, Apr 22 2009
(PARI) Vec(1/(1-x*(1-8*x)) + O(x^40)) \\ Michel Marcus, Jan 29 2016
(Magma) I:=[1, 1]; [n le 2 select I[n] else Self(n-1) - 8*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 19 2018
KEYWORD
sign,easy
AUTHOR
Philippe Deléham, Oct 26 2008
STATUS
approved

  NODES
COMMUNITY 1
INTERN 1