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.

A168304 The fifth left hand column of triangle A167565.

Original entry on oeis.org

24, 368, 2736, 13712, 53121, 171258, 480711, 1210572, 2793219, 5996562, 12117677, 23257104, 42696758, 75408396, 128723898, 213203256, 343741122, 540958044, 832928118, 1257300704, 1863880095, 2717733590, 3902905305, 5526820260, 7725470805
Offset: 5

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Author

Johannes W. Meijer, Nov 23 2009

Keywords

Crossrefs

Equals the fifth left hand column of triangle A167565.
Other left hand columns are A000027, A000292, A167566 and A167567.

Programs

  • Magma
    [(321*n^9-4500*n^8+25506*n^7-75096*n^6+121905*n^5- 104580*n^4+2736*n^2+37164*n^3-3456*n)/362880: n in [5..40]]; // Vincenzo Librandi, Jul 18 2016
  • Mathematica
    LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{24, 368, 2736, 13712, 53121, 171258, 480711, 1210572, 2793219, 5996562},50] (* G. C. Greubel, Jul 17 2016 *)

Formula

a(n) = (321*n^9 - 4500*n^8 + 25506*n^7 - 75096*n^6 + 121905*n^5 - 104580*n^4 + 2736*n^2 + 37164*n^3 - 3456*n)/9!.
G.f.: (z^4 + 32*z^3 + 136*z^2 + 128*z + 24)/(1-z)^10.
a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10).
a(n) - 9*a(n-1) + 36*a(n-2) - 84*a(n-3) + 126*a(n-4) - 126*a(n-5) + 84*a(n-6) - 36*a(n-7) + 9*a(n-8) - a(n-9) = 321.