A107389 Expansion of x*(1-6*x+7*x^2)/( (1-x)*(1+x)*(1-5*x+x^2)).

0, 1, -1, 2, 5, 31, 144, 697, 3335, 15986, 76589, 366967, 1758240, 8424241, 40362959, 193390562, 926589845, 4439558671, 21271203504, 101916458857, 488311090775, 2339638995026, 11209883884349, 53709780426727, 257339018249280, 1232985310819681, 5907587535849119

Offset: 0

Author

Roger L. Bagula, May 24 2005, corrected Sep 04 2008

Keywords

• sign
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (5,0,-5,1).

Programs

Mathematica

LinearRecurrence[{5,0,-5,1},{0,1,-1,2},30] (* Harvey P. Dale, Sep 17 2020 *)

PARI

concat(0,Vec((1-6*x+7*x^2)/(1-x)/(1+x)/(1-5*x+x^2)+O(x^98))) \\ Charles R Greathouse IV, Jan 25 2012

Formula

a(n)-a(n-2) = A030221(n-3), n>2. - R. J. Mathar, Dec 17 2017

Extensions

Irregular sign at a(2) switched by R. J. Mathar, Jan 24 2012