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A232759
Number of tilings of a 7 X 4n rectangle with 7n tetrominoes of any shape.
2
1, 9157, 657253434, 58480141962875, 5316709999497259059, 484393789403397886429249, 44141190389848159904786733934, 4022519784390988451174562198889336, 366566828291367228800261059891047626895, 33404748935117787113145811582089363383972226
OFFSET
0,2
LINKS
S. Butler, J. Ekstrand, S. Osborne, TETRIS Tiling, AMS Spring Central Sectional, Iowa State University, April 27-28 2013
Wikipedia, Tetris
Wikipedia, Tetromino
CROSSREFS
Quadrisection of column k=7 of A230031.
Sequence in context: A205922 A256766 A210140 * A250149 A243969 A231424
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 29 2013
STATUS
approved