These are classified according to
- the number of NODES;
- according to CONNECTION BETWEEN NODES or LACK OF CONNECTION.
Here are the first four orders. You may experiment to extend the Order.
1 * 2 * * *----------* 3 * * * * / / \ * * *-----* *----* *---* 4 * * * * * * * * | |\ | | \ * * *---* *---* *--* *---* *---* *----* *----* |\ |\ | |\ /| | \ | \ | | \/ | | \ | \| | /\ | *---* *---* *----* *----* *----* *----* * * | | | | / | | | | / | | | | / *----* *----* *----*