A251076 Number of tilings of a 21 X n rectangle using 3n heptominoes of shape I.

1, 1, 1, 1, 1, 1, 1, 53, 141, 271, 449, 681, 973, 1331, 9391, 26803, 60953, 122641, 226921, 394031, 650413, 2039288, 5611209, 13694084, 30417897, 62763334, 122046063, 225958222, 532867801, 1319078776, 3196149101, 7383041514, 16186545853, 33788903208

Offset: 0

Author

Alois P. Heinz, Nov 29 2014

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..500
• Wikipedia, Heptomino

Crossrefs

Column k=7 of A251072.

Cf. A250664.