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.

A203532 v(n+1)/v(n), where v=A203530.

Original entry on oeis.org

10, 168, 3315, 76608, 2661120, 113667840, 4311354600, 178738560000, 11178747740160, 791853627801600, 44783640216315000, 2693449157020876800, 246209683227475968000, 17126298576096297588000, 1253392853589570355200000
Offset: 1

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Author

Clark Kimberling, Jan 03 2012

Keywords

Crossrefs

Programs

  • Mathematica
    t = Table[If[PrimeQ[k], 0, k], {k, 1, 100}];
    composite = Rest[Rest[Union[t]]]       (* A002808 *)
    f[j_] := composite[[j]]; z = 20;
    v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}]
    d[n_] := Product[(i - 1)!, {i, 1, n}]  (* A000178 *)
    Table[v[n], {n, 1, z}]                 (* A203530 *)
    Table[v[n + 1]/v[n], {n, 1, z - 1}]    (* A203532 *)
    Table[v[n]/d[n], {n, 1, 20}]           (* A203533 *)