A028166 Expansion of 1/((1-5x)(1-6x)(1-7x)(1-9x)).

1, 27, 460, 6330, 76951, 863457, 9169210, 93598560, 928041301, 9002652087, 85889800360, 809002365990, 7544820424051, 69822238375917, 642271794705910, 5880216219628620, 53636500167577201, 487828126104034947

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (27,-269,1173,-1890)

Formula

a(n) = 27*a(n-1) - 2 69*a(n-2) + 1173*a(n-3) - 1890*a(n-4), n >= 4. - Vincenzo Librandi, Mar 19 2011

a(n) = 16*a(n-1) - 63*a(n-2) + 6^(n+1) - 5^(n+1), n >= 2. - Vincenzo Librandi, Mar 19 2011

a(n) = -7^(n+3)/4 + 2*6^(n+2) + 3*9^(n+2)/8 - 5^(n+3)/8. - R. J. Mathar, Mar 19 2011

Mathematica

CoefficientList[Series[1/((1-5x)(1-6x)(1-7x)(1-9x)), {x, 0, 30}], x] (* or *)
LinearRecurrence[{27, -269, 1173, -1890}, {1, 27, 460, 6330}, 30]  (* Harvey P. Dale, Apr 26 2011 *)

Crossrefs

Sequence in context: A004326 A233022 A289902 * A028135 A028132 A028089

Adjacent sequences: A028163 A028164 A028165 * A028167 A028168 A028169

Keyword

nonn

Author

N. J. A. Sloane

Status

approved