0,2

A 5-pillow is a generalized Aztec pillow. The 5-pillow of order n is a rotationally-symmetric region. It has a 2 X 2n central band of squares and then steps up from this band with steps of 5 horizontal squares to every 1 vertical square and steps down with steps of 1 horizontal square to every 1 vertical square.

C. Hanusa (2005). A Gessel-Viennot-Type Method for Cycle Systems with Applications to Aztec Pillows. PhD Thesis. University of Washington, Seattle, USA.

The number of domino tilings of the 5-pillow of order 6 is 1666=7^2*34.

A112836 can be decomposed as A112837^2 times A112838, where A112838 is not necessarily squarefree.

3-pillows: A112833-A112835; 7-pillows: A112839-A112841; 9-pillows: A112842-A112844.

Sequence in context: A059103 A365709 A260709 * A353719 A353722 A105905

Adjacent sequences: A112833 A112834 A112835 * A112837 A112838 A112839

Christopher Hanusa (chanusa(AT)math.binghamton.edu), Sep 21 2005

approved