This page contains a gallery of symmetric forms that you can make of the 16 onesided Bridged Triamonds. Ed Pegg gave me a hint to try the onesided version. Different from the twosided version there are hexagon symmetric forms possible.
135 * 12 solutions
1586 * 12 solutions
no solution
2706 * 12 solutions
175 * 12 solutions
6279 * 12 solutions
3681 * 12 solutions
67 * 12 solutions
1810 * 12 solutions
36 * 12 solutions
58 * 12 solutions
13117 * 6 solutions
27695 * 6 solutions
237 * 6 solutions
677 * 6 solutions
196 * 6 solutions
1124 * 6 solutions
9018 * 6 solutions
160551 * 6 solutions
390 * 3 solutions
45920 * 3 solutions
205 * 3 solutions
67411 * 2 solutions
87 * 4 solutions
75 * 4 solutions