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.

A359268 a(n) is the least k such that A359194(k) = A359194(n).

Original entry on oeis.org

0, 1, 0, 3, 4, 1, 6, 7, 8, 9, 0, 11, 12, 13, 14, 15, 16, 17, 18, 3, 4, 1, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 6, 7, 8, 9, 0, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69
Offset: 0

Views

Author

Rémy Sigrist, Dec 23 2022

Keywords

Examples

			The first terms, alongside A359194(n), are:
  n   a(n)  A359194(n)
  --  ----  ----------
   0     0           1
   1     1           0
   2     0           1
   3     3           6
   4     4           3
   5     1           0
   6     6          13
   7     7          10
   8     8           7
   9     9           4
  10     0           1
  11    11          30
  12    12          27
		

Crossrefs

Programs

  • PARI
    b(n) = if(n, bitneg(3*n, exponent(3*n)+1), 1)
    a(n) = { my (v=b(n)); while (n, my (x=exponent(n)); if (b(n-2^x)==v, n-=2^x, break)); return (n) }

Formula

a(n) = 0 iff n belongs to A020988.
a(n) = 1 iff n belongs to A002450 \ {0}.