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.

A295573 Array read by upwards antidiagonals: T(n,k) = nk + floor(phi n) ceiling(phi k) where phi = (1 + sqrt(5))/2.

Original entry on oeis.org

3, 8, 6, 11, 16, 8, 16, 22, 21, 11, 21, 32, 29, 29, 14, 24, 42, 42, 40, 37, 16, 29, 48, 55, 58, 51, 42, 19, 32, 58, 63, 76, 74, 58, 50, 21, 37, 64, 76, 87, 97, 84, 69, 55, 24, 42, 74, 84, 105, 111, 110, 100, 76, 63, 27, 45, 84, 97, 116, 134, 126, 131, 110, 87, 71, 29, 50, 90, 110, 134, 148, 152, 150, 144, 126, 98, 76, 32
Offset: 1

Views

Author

N. J. A. Sloane, Dec 03 2017

Keywords

Comments

This is a hybrid of the Porta-Stolarsky star product (A101858) and the Arnoux product (A101866)

Examples

			The array begins:
3, 6, 8, 11, 14, 16, 19, 21, 24, 27, 29, 32, ...
8, 16, 21, 29, 37, 42, 50, 55, 63, 71, 76, 84, ...
11, 22, 29, 40, 51, 58, 69, 76, 87, 98, 105, 116, ...
16, 32, 42, 58, 74, 84, 100, 110, 126, 142, 152, 168, ...
21, 42, 55, 76, 97, 110, 131, 144, 165, 186, 199, 220, ...
24, 48, 63, 87, 111, 126, 150, 165, 189, 213, 228, 252, ...
29, 58, 76, 105, 134, 152, 181, 199, 228, 257, 275, 304, ...
32, 64, 84, 116, 148, 168, 200, 220, 252, 284, 304, 336, ...
...
		

Crossrefs

Cf. A001622, A101858, A101866, A371382 (main diagonal).

Programs

  • Maple
    T := proc(n, k) local phi;
            phi := (1+sqrt(5))/2 ;
            n*k+floor(n*phi)*ceil(phi*k) ;
    end proc:
    for n from 1 to 12 do
    lprint([seq(T(n-i+1,i),i=1..n)]);
    od: # by antidiagonals
    for n from 1 to 12 do
    lprint([seq(T(n,i),i=1..12)]);
    od: # by rows
  • Mathematica
    A295573[n_, k_] := n*k + Floor[n * GoldenRatio] * Ceiling[k * GoldenRatio];
    Table[A295573[n-k+1,k], {n, 15}, {k, n}] (* Paolo Xausa, Mar 20 2024 *)