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.

A348684 Triangle read by rows, T(n, k) = 2*n - HammingWeight(k), for 0 <= k <= n.

Original entry on oeis.org

0, 2, 1, 4, 3, 3, 6, 5, 5, 4, 8, 7, 7, 6, 7, 10, 9, 9, 8, 9, 8, 12, 11, 11, 10, 11, 10, 10, 14, 13, 13, 12, 13, 12, 12, 11, 16, 15, 15, 14, 15, 14, 14, 13, 15, 18, 17, 17, 16, 17, 16, 16, 15, 17, 16, 20, 19, 19, 18, 19, 18, 18, 17, 19, 18, 18
Offset: 0

Views

Author

Peter Luschny, Oct 29 2021

Keywords

Examples

			Triangle starts:
[0]  0;
[1]  2,  1;
[2]  4,  3,  3;
[3]  6,  5,  5,  4;
[4]  8,  7,  7,  6,  7;
[5] 10,  9,  9,  8,  9,  8;
[6] 12, 11, 11, 10, 11, 10, 10;
[7] 14, 13, 13, 12, 13, 12, 12, 11;
[8] 16, 15, 15, 14, 15, 14, 14, 13, 15;
[9] 18, 17, 17, 16, 17, 16, 16, 15, 17, 16;
		

Crossrefs

Programs

  • Maple
    HammingWeight := n -> add(i, i = convert(n, base, 2)):
    A348684 := (n, k) -> 2*n - HammingWeight(k):
    seq(seq(A348684(n, k), k = 0..n), n = 0..10);
  • Mathematica
    Table[2*n - DigitCount[k, 2, 1], {n, 0, 10}, {k, 0, n}] // Flatten (* Amiram Eldar, Oct 30 2021 *)