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.

A129925 Triangular sequence based on A002301 and the alternating groups a prime -adic: t(n,m)=n!/Prime[m] for n>=Prime[m].

Original entry on oeis.org

1, 3, 2, 12, 8, 60, 40, 24, 360, 240, 144, 2520, 1680, 1008, 720, 20160, 13440, 8064, 5760, 181440, 120960, 72576, 51840, 1814400, 1209600, 725760, 518400, 19958400, 13305600, 7983360, 5702400, 3628800, 239500800, 159667200, 95800320, 68428800
Offset: 1

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Author

Roger L. Bagula, Jun 06 2007

Keywords

Comments

Alternating groups are: An->n!/2 for n>=2 If the tritonic or triple symmetric groups are: Tn->n!/3 for n>=4 Then the pentatonic would be: Pn->n!/5 for n>=5 General: ( triangular sequence) G(m)n=n!/Prime[m] for n>=Prime[m]

Examples

			{1},
{3, 2},
{12, 8},
{60, 40, 24},
{360, 240, 144},
{2520, 1680, 1008, 720},
{20160, 13440, 8064, 5760},
{181440, 120960, 72576, 51840},
{1814400, 1209600, 725760, 518400},
		

Crossrefs

Cf. A002301.

Programs

  • Mathematica
    g[n_, m_] = If[n >= Prime[m], n!/Prime[m], {}]; a = Table[Flatten[Table[g[n, m], {m, 1, n}]], {n, 1, 23}]; Flatten[a]

Formula

t(n,m)=n!/Prime[m] for n>=Prime[m]