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A233380 X-coordinate of the bottom left corner of the n X 1 brick in the greedy tiling of the first quadrant with bricks of height 1 and width 1, 2, 3... (See Comments for precise definition). 2

%I #14 Apr 25 2016 12:00:16

%S 0,1,0,3,7,3,0,12,9,7,0,20,18,17,11,0,32,31,49,68,49,31,26,16,0,88,70,

%T 53,49,40,25,0,114,97,81,78,70,56,32,0,147,131,116,114,107,94,71,40,0,

%U 188,173,159,158,152,140,118,88,49,0,238,224,211,298,285

%N X-coordinate of the bottom left corner of the n X 1 brick in the greedy tiling of the first quadrant with bricks of height 1 and width 1, 2, 3... (See Comments for precise definition).

%C We tile the first quadrant according to the following rules:

%C (a) We use bricks of height 1 and width 1, 2, 3, ...

%C (b) The bricks are laid by increasing size, without overlap.

%C (c) The left border of any brick must lie on the Y-axis or match the right border of a smaller brick.

%C (d) The bottom border of any brick must lie on the X-axis or touch all along the top border of smaller bricks.

%C (e) When multiple positions are possible, we choose the leftmost one.

%C A233381 gives the Y-coordinate.

%H Paul Tek, <a href="/A233380/b233380.txt">Table of n, a(n) for n = 1..10000</a>

%H Paul Tek, <a href="/A233380/a233380.txt">PERL program for this sequence</a>

%H Paul Tek, <a href="/A233380/a233380.png">Illustration of the first 1022 bricks</a>

%H Paul Tek, <a href="/A233380/a233380_1.png">Illustration of the first 9986 bricks</a>

%e The following diagram depicts the first 7 bricks:

%e +-------------+

%e | 7 |

%e +-----+-------+---+

%e | 3 | 6 |

%e +-+---+-------+---+-----+

%e |1| 2 | 4 | 5 |

%e +-+---+-------+---------+---> X

%e 0 1 2 3 4 5 6 7 8 9 ...

%e Hence:

%e a(1)=a(3)=a(7)=0

%e a(2)=1

%e a(4)=a(6)=3

%e a(5)=7

%o (Perl) See Link section.

%Y Cf. A233381.

%K nonn

%O 1,4

%A _Paul Tek_, Dec 08 2013

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Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)