A089947 G.f.: (1-x)^9/((1-5*x+6*x^2-4*x^3+x^4)*(-1+4*x-3*x^2+x^3)*(1-3*x+x^2)*(-1+2*x)).

1, 5, 25, 115, 500, 2092, 8512, 33910, 132892, 514079, 1968021, 7470434, 28160354, 105542777, 393672627, 1462503264, 5414896000, 19991387639, 73628208598, 270614786791, 992880076249, 3637400475618, 13308475404934, 48639360355243, 177597694845849

Offset

0,2

References

A. Burstein and T. Mansour, Words restricted by 3-letter ..., Annals. Combin., 7 (2003), 1-14; see Th. 3.6, case k=5.

Links

Table of n, a(n) for n=0..24.

A. Burstein and T. Mansour, Words restricted by 3-letter ....

Index entries for linear recurrences with constant coefficients, signature (14, -81, 254, -481, 588, -485, 270, -98, 21, -2).

Mathematica

CoefficientList[Series[(1-x)^9/((1-5x+6x^2-4x^3+x^4)(-1+4x-3x^2+x^3)(1-3x+x^2)(-1+2x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{14, -81, 254, -481, 588, -485, 270, -98, 21, -2}, {1, 5, 25, 115, 500, 2092, 8512, 33910, 132892, 514079}, 30] (* Harvey P. Dale, Oct 03 2015 *)

Crossrefs

Cf. A061667, A089883, A089932.

Sequence in context: A124534 A369769 A261383 * A267467 A123890 A123894

Adjacent sequences: A089944 A089945 A089946 * A089948 A089949 A089950

Keyword

nonn

Author

N. J. A. Sloane, Jan 18 2004

Status

approved