%0 Journal Article %T A Construction of the "2221" Planar Algebra %A Richard Han %J Mathematics %D 2011 %I arXiv %X In this paper, we construct the "2221" subfactor planar algebra by finding it as a subalgebra of the graph planar algebra of its principal graph. In particular, we give a presentation of the "2221" subfactor planar algebra consisting of generators and relations. As a corollary, we have a planar algebra proof of the existence of a subfactor with principal graph "2221". To show the subfactor property, we use the jellyfish algorithm for evaluating closed diagrams. Lastly, we show uniqueness up to conjugation of "2221". %U http://arxiv.org/abs/1102.2052v1