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.

A359255 Number of steps to reach a maximum starting with n in the map x->A359194(x) (binary complement of 3n), or -1 if n goes to infinity.

Original entry on oeis.org

0, 0, 0, 7, 8, 0, 6, 1, 2, 9, 0, 15, 28, 5, 1, 11, 12, 29, 10, 7, 8, 0, 2, 31, 4, 21, 5, 27, 2962, 1, 14, 23, 24, 2963, 22, 3, 8, 13, 6, 0, 0, 9, 0, 2961, 2, 33, 26, 11, 74, 4, 1591, 69, 20, 5, 3, 3, 34, 9, 30, 1, 16, 1, 76, 11
Offset: 0

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Author

Hans Havermann, Dec 22 2022

Keywords

Comments

The corresponding maxima reached are in A359208. The indices at which zeros appear here are in A359209.

Crossrefs

Programs

  • Mathematica
    f[n_] := FromDigits[BitXor[1, IntegerDigits[3*n, 2]], 2]; Table[c=m=0; n=r=i; While[n!=0, c++; n=f[n]; If[n>r, m=c; r=n]]; m, {i, 0, 63}]
  • Python
    def f(n): return 1 if n == 0 else (m:=3*n)^((1 << m.bit_length())-1)
    def a(n):
        i, fi, m, mi = 0, n, n, 0
        while fi != 0:
            i, fi = i+1, f(fi)
            if fi > m: m, mi = fi, i
        return mi
    print([a(n) for n in range(64)]) # Michael S. Branicky, Dec 22 2022