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.

A362090 a(n) = A328749(A362089(n)).

Original entry on oeis.org

0, -1, 1, -2, -5, -3, 2, 3, 5, -4, -9, -7, -10, -21, -19, -6, -13, -11, 4, 7, 9, 6, 11, 13, 10, 19, 21, -8, -17, -15, -18, -37, -35, -14, -29, -27, -20, -41, -39, -42, -85, -83, -38, -77, -75, -12, -25, -23, -26, -53, -51, -22, -45, -43, 8, 15, 17, 14, 27, 29
Offset: 0

Views

Author

Rémy Sigrist, Apr 08 2023

Keywords

Comments

Every integer appears once in the sequence.

Examples

			For n = 5, the base-3 expansion of 5 is "12", so the base-3 expansion of A362089(5) is "102", and a(5) = -2^2 + 2^0 = -3.
		

Crossrefs

Programs

  • PARI
    a(n) = { if (n==0, 0, n%3, 4*a(n\3) + (-1)^(n%3), 2*a(n/3)); }
    
  • Python
    from gmpy2 import digits
    def A362090(n): return sum((-(1<Chai Wah Wu, Apr 12 2023