A247744 Total number of X shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.

0, 0, 0, 1, 8, 76, 752, 7728, 76138, 683740, 6016612, 52483260, 453461612, 3873299197, 32718505462, 274368261226, 2287565667766, 18973561019204, 156622182476404, 1287479429817295, 10545476231546336, 86101164740284870, 700977394316933694, 5692064258367318333

Offset

0,5

Links

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

Wikipedia, Pentomino

Formula

a(n) = Sum_{k>0} k * A247711(n,k).

Crossrefs

Cf. A174249, A233427, A247711.

Sequence in context: A247828 A303736 A083234 * A144851 A233827 A231286

Adjacent sequences: A247741 A247742 A247743 * A247745 A247746 A247747

Keyword

nonn

Author

Alois P. Heinz, Sep 23 2014

Status

approved