(%i1) load("graphs"); (%i2) fourminoesgraph: create_graph([1,2,3,4,5], [ [1,2],[1,4], [2,3],[2,4],[2,5], [3,4],[3,5], [4,5] ]); (%o2) GRAPH(5 vertices, 8 edges) (%i3) /* The numbering of the pentominoes followed http://oeis.org/wiki/User:FUNG_Cheok_Yin/pent */ (%i4) fiveminoesgraph: create_graph([1,2,3,4,5,6,7,8,9,10,11,12], [ [1,2],[1,3], [2,3],[2,4],[2,5],[2,12],[2,7],[2,8],[2,11],[2,9], [3,4],[3,5],[3,6],[3,7],[3,8],[3,9],[3,11],[3,12], [4,5],[4,6],[4,7],[4,8],[4,9],[4,11],[4,12], [5,7],[5,8],[5,9],[5,10],[5,11],[5,12], [6,7],[6,11], [7,8],[7,9],[7,11],[7,12], [8,9],[8,11],[8,12],[8,10], [9,10],[9,11],[9,12], [10,11],[10,12], [11,12] ]); (%o4) GRAPH(12 vertices, 47 edges) /* original on Feb 11 2020; revised on Apr 13 2020, thanks to Sean A. Irvine's data and Freddy Barrera's image*/