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.

A307505 Number T(n,k) of partitions of n into distinct parts whose bitwise XOR equals k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Apr 11 2019

Keywords

Examples

			Triangle T(n,k) begins:
  1;
  0, 1;
  0, 0, 1;
  0, 0, 0, 2;
  0, 0, 1, 0, 1;
  0, 1, 0, 0, 0, 2;
  1, 0, 0, 0, 1, 0, 2;
  0, 0, 0, 0, 0, 0, 0, 5;
  0, 0, 0, 0, 1, 0, 4, 0, 1;
  0, 1, 0, 0, 0, 4, 0, 1, 0, 2;
  1, 0, 1, 0, 5, 0, 0, 0, 1, 0, 2;
  ...
		

Crossrefs

Bisection (even part) of column k=0 gives A307506.
Row sums give A000009.
Main diagonal gives A050315.
Cf. A050314.

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, x^k, `if`(i<1, 0,
          b(n, i-1, k)+b(n-i, min(n-i, i-1), Bits[Xor](i, k))))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n$2, 0)):
    seq(T(n), n=0..14);

Formula

T(n,k) = 0 if n+k is odd.