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.

A065934 Permutation of N induced by the order-preserving bijection QuQR1toQuQR2 on rationals.

Original entry on oeis.org

1, 5, 13, 2, 23, 25, 3, 9, 20, 11, 95, 49, 6, 223, 57, 4, 39, 80, 10, 45, 92, 47, 383, 97, 12, 415, 208, 55, 3583, 225, 29, 17, 36, 19, 159, 320, 40, 83, 42, 22, 183, 368, 46, 189, 380, 191, 1535, 193, 24, 799, 400, 103, 6655, 3328, 52, 220, 445, 895, 57343, 897
Offset: 1

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Author

Antti Karttunen, Dec 07 2001

Keywords

Comments

This permutation converts the domain between the mappings N2QuQR1 and N2QuQR2 given in A065936 and A065937, i.e. N2QuQR1(j) = N2QuQR2(a[j])

Crossrefs

Inverse permutation: A065935. For other needed Maple procedures, see A007305, A047679 and A054424. A065939[n] = a[A065938[n]].

Programs

  • Maple
    [seq(QuQR1toQuQR2(j),j=1..128)];
    QuQR1toQuQR2 := proc(n) local m; m := n + 2^floor_log_2(n); frac2position_in_whole_SB_tree(Q0_1toQ(SternBrocotTreeNum(m)/SternBrocotTreeDen(m))); end;
    Q0_1toQ := proc(rr) local r,i; r := rr; i := 0; while(r >= 1/2) do r := 2*(r-(1/2)); i := i+1; od; RETURN(i + (2*r)); end;