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.

A369311 Square array A(n, k), n >= 0, k > 0, read by upwards antidiagonals: P(A(n, k)) is the remainder of the polynomial long division of P(n) by P(k) (where P(m) denotes the polynomial over GF(2) whose coefficients are encoded in the binary expansion of the nonnegative integer m).

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 2, 1, 0, 0, 1, 1, 3, 2, 1, 0, 0, 0, 0, 0, 3, 2, 1, 0, 0, 1, 0, 1, 1, 3, 2, 1, 0, 0, 0, 1, 2, 0, 2, 3, 2, 1, 0, 0, 1, 1, 3, 3, 3, 3, 3, 2, 1, 0, 0, 0, 0, 0, 2, 0, 2, 4, 3, 2, 1, 0, 0, 1, 0, 1, 2, 1, 1, 5, 4, 3, 2, 1, 0
Offset: 0

Views

Author

Rémy Sigrist, Jan 19 2024

Keywords

Comments

For any number m >= 0 with binary expansion Sum_{k >= 0} b_k * 2^k, P(m) = Sum_{k >= 0} b_k * X^k.

Examples

			Array A(n, k) begins:
  n\k | 1  2  3  4  5  6  7  8  9  10  11  12
  ----+--------------------------------------
    0 | 0  0  0  0  0  0  0  0  0   0   0   0
    1 | 0  1  1  1  1  1  1  1  1   1   1   1
    2 | 0  0  1  2  2  2  2  2  2   2   2   2
    3 | 0  1  0  3  3  3  3  3  3   3   3   3
    4 | 0  0  1  0  1  2  3  4  4   4   4   4
    5 | 0  1  0  1  0  3  2  5  5   5   5   5
    6 | 0  0  0  2  3  0  1  6  6   6   6   6
    7 | 0  1  1  3  2  1  0  7  7   7   7   7
    8 | 0  0  1  0  2  2  1  0  1   2   3   4
    9 | 0  1  0  1  3  3  0  1  0   3   2   5
   10 | 0  0  0  2  0  0  3  2  3   0   1   6
   11 | 0  1  1  3  1  1  2  3  2   1   0   7
   12 | 0  0  0  0  3  0  2  4  5   6   7   0
		

Crossrefs

See A369312 for the corresponding quotients.

Programs

  • PARI
    A(n, k) = { fromdigits(lift(Vec( (Mod(1, 2) * Pol(binary(n))) % (Mod(1, 2) * Pol(binary(k))))), 2) }