A028120 Expansion of 1/((1-4x)(1-5x)(1-8x)(1-9x)).

1, 26, 431, 5824, 70077, 783510, 8335867, 85622108, 857084393, 8414359954, 81378676743, 777830951352, 7365015041749, 69207262292558, 646271819803859, 6003846344524756, 55534562590626945, 511814373212664522

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (26,-245,988,-1440)

Formula

From Vincenzo Librandi, Mar 17 2011: (Start)

a(n) = 26*a(n-1) - 245*a(n-2) + 988*a(n-3) - 1440*a(n-4), n >= 4.

a(n) = 17*a(n-1) - 72*a(n-2) + 5^(n+1) - 4^(n+1), n >= 2. (End)

a(n) = -2*8^(n+2)/3 + 9^(n+3)/20 - 4^(n+2)/5 + 5^(n+3)/12. - R. J. Mathar, Mar 18 2011

Mathematica

CoefficientList[Series[1/((1-4x)(1-5x)(1-8x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{26, -245, 988, -1440}, {1, 26, 431, 5824}, 30] (* Harvey P. Dale, Jul 19 2015 *)

Crossrefs

Sequence in context: A028165 A218896 A028131 * A028079 A028117 A028076

Adjacent sequences: A028117 A028118 A028119 * A028121 A028122 A028123

Keyword

nonn

Author

N. J. A. Sloane

Status

approved