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.

Showing 1-1 of 1 results.

A367194 The y-coordinate of the point where x + y = n, x and y are integers and x/y is as close as possible to Pi.

Original entry on oeis.org

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

Views

Author

Colin Linzer, Nov 13 2023

Keywords

Comments

a(n) is nondecreasing; lim_{n->oo} a(n) = oo.
Swapping the x and y coordinate of the sequence does not yield the sequence defined as the point where x + y = n, x and y are integers and x/y is as close as possible to 1/Pi even when excluding terms that would lead to a division by 0.

Examples

			For n = 3, the possible fractions are (0,3), (1,2), (2,1) as any negative values would would be further from Pi than 0/3. The closest fraction to Pi out of these is 2/1 so a(3) = 1.
		

Crossrefs

Cf. A367193 (x-coordinate), A000796, A002486.

Programs

  • Maple
    f:= proc(n) local x;
       x:= floor(n/(1+Pi));
       if x = 0 then return 1 fi;
       if is((n-x)/x + (n-x-1)/(x+1) < 2*Pi) then x else x+1 fi
    end proc:
    map(f, [$1..100]); # Robert Israel, Nov 13 2023

Formula

a(n) is always either ceiling(n/(1+Pi)) or floor(n/(1+Pi)).
Showing 1-1 of 1 results.