A247708 Number T(n,k) of tilings of a 5 X n rectangle with pentominoes of any shape and exactly k pentominoes of shape U; triangle T(n,k), n>=0, read by rows.
1, 1, 5, 39, 16, 1, 369, 120, 12, 2908, 1000, 98, 19185, 7474, 1228, 60, 3, 137200, 63896, 12448, 1092, 53, 1022915, 540562, 120034, 12676, 590, 4, 7606043, 4365686, 1084022, 140512, 8836, 250, 5, 55699672, 34738058, 9663366, 1466724, 124242, 5984, 166
Offset: 0
Examples
T(3,2) = 1: ._____. | ._. | |_| |_| |_. ._| | |_| | |_____| . Triangle T(n,k) begins: 00 : 1; 01 : 1; 02 : 5; 03 : 39, 16, 1; 04 : 369, 120, 12; 05 : 2908, 1000, 98; 06 : 19185, 7474, 1228, 60, 3; 07 : 137200, 63896, 12448, 1092, 53; 08 : 1022915, 540562, 120034, 12676, 590, 4; 09 : 7606043, 4365686, 1084022, 140512, 8836, 250, 5; 10 : 55699672, 34738058, 9663366, 1466724, 124242, 5984, 166;
Links
- Alois P. Heinz, Rows n = 0..175, flattened
- Wikipedia, Pentomino
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