cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A089883 Expansion of (1-4*x+6*x^2-3*x^3)/((1-3*x)*(1-2*x)*(1-3*x+x^2)).

Original entry on oeis.org

1, 4, 16, 60, 214, 736, 2464, 8082, 26092, 83188, 262582, 822144, 2557120, 7910050, 24357580, 74720436, 228485158, 696795712, 2120116768, 6438264498, 19518937516, 59091592564, 178675498006, 539694923520, 1628691435904, 4911230068546, 14799559211404
Offset: 0

Views

Author

N. J. A. Sloane, Jan 18 2004

Keywords

Comments

I did not study this paper carefully, but it appears that this g.f. might be wrong and the correct version should be that in A089932.

Links

Programs

  • Mathematica
    LinearRecurrence[{8, -22, 23, -6}, {1, 4, 16, 60}, 27] (* Jean-François Alcover, Jan 07 2019 *)

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)).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Jan 18 2004

Keywords

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

Crossrefs

Cf. A061667, A089883, A089932.

Programs

  • 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 *)
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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