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.

A195183 Fractalization of the prime marker sequence A089026.

Original entry on oeis.org

1, 1, 2, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 5, 6, 4, 1, 2, 3, 5, 6, 4, 1, 2, 3, 5, 7, 8, 6, 4, 1, 2, 3, 5, 7, 9, 8, 6, 4, 1, 2, 3, 5, 7, 10, 9, 8, 6, 4, 1, 2, 3, 5, 7, 10, 9, 8, 6, 4, 1, 2, 3, 5, 7, 11, 12, 10, 9, 8, 6, 4, 1, 2, 3, 5, 7, 11, 12, 10, 9, 8, 6, 4, 1, 2, 3, 5, 7, 11, 13, 14, 12
Offset: 1

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Author

Clark Kimberling, Sep 10 2011

Keywords

Comments

See A194959 for a discussion of fractalization and the interspersion fractally induced by a sequence. (The prime marker sequence A089026 is defined by p(n)=n if n is prime and p(n)=1 otherwise.)

Crossrefs

Programs

  • Mathematica
    Table[p[n], {n, 1, 90}]  (* A089026 *)
    g[1] = {1}; g[n_] := Insert[g[n - 1], n, p[n]]
    f[1] = g[1]; f[n_] := Join[f[n - 1], g[n]]
    f[20] (* A195183 *)
    row[n_] := Position[f[30], n];
    u = TableForm[Table[row[n], {n, 1, 5}]]
    v[n_, k_] := Part[row[n], k];
    w = Flatten[Table[v[k, n - k + 1], {n, 1, 13}, {k, 1, n}]]  (* A195184 *)
    q[n_] := Position[w, n]; Flatten[Table[q[n], {n, 1, 80}]]  (* A195185 *)