This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A112836 #6 Sep 17 2023 00:26:11 %S A112836 1,2,5,13,52,261,1666,14400,159250,2308545,43718544,1079620569, %T A112836 34863330980,1466458546176,80646187346132,5787269582487581, %U A112836 541901038236234048,66279540183479379277,10578427028263503488000 %N A112836 Number of domino tilings of a 5-pillow of order n. %C A112836 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. %D A112836 C. Hanusa (2005). A Gessel-Viennot-Type Method for Cycle Systems with Applications to Aztec Pillows. PhD Thesis. University of Washington, Seattle, USA. %e A112836 The number of domino tilings of the 5-pillow of order 6 is 1666=7^2*34. %Y A112836 A112836 can be decomposed as A112837^2 times A112838, where A112838 is not necessarily squarefree. %Y A112836 3-pillows: A112833-A112835; 7-pillows: A112839-A112841; 9-pillows: A112842-A112844. %K A112836 nonn %O A112836 0,2 %A A112836 Christopher Hanusa (chanusa(AT)math.binghamton.edu), Sep 21 2005