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

0,8

Links

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

Wikipedia, Heptomino

Crossrefs

Column k=7 of A251072.

Cf. A250664.

Sequence in context: A239721 A142259 A161611 * A142043 A175600 A142417

Adjacent sequences: A251073 A251074 A251075 * A251077 A251078 A251079

Keyword

nonn

Author

Alois P. Heinz, Nov 29 2014

Status

approved