A026324 Expansion of 1/((1-2*x)*(1-6*x)*(1-7*x)*(1-8*x)).

1, 23, 341, 4147, 45045, 455091, 4373797, 40541699, 365712149, 3230463379, 28067769093, 240654781731, 2041291828213, 17162300683187, 143239714105829, 1188212150789443, 9805989936743637, 80575358596047315

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (23,-188,628,-672).

Formula

a(n) = -2^n/15 +27*6^n -343*7^n/5 +128*8^n/3. - R. J. Mathar, Jun 23 2013

E.g.f.: exp(2*x)*(640*exp(6*x) - 1029*exp(5*x) + 405*exp(4*x) - 1)/15. - Stefano Spezia, Dec 20 2025

Mathematica

CoefficientList[Series[1/((1-2x)(1-6x)(1-7x)(1-8x)), {x, 0, 20}], x] (* or *) LinearRecurrence[{23, -188, 628, -672}, {1, 23, 341, 4147}, 20] (* Harvey P. Dale, Feb 25 2026 *)

Crossrefs

Sequence in context: A028059 A299710 A028055 * A028039 A002118 A025993

Adjacent sequences: A026321 A026322 A026323 * A026325 A026326 A026327

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved