Self-Replicating Resistors

In an electrical network, if resistors x and y are placed in series their total resistance is x + y; if they're placed in parallel it's 1/(1/x + 1/y).

This offers an intriguing opportunity for self-reference. Each of the networks above contains four resistors with values 1, 2, 3, and 4, and the total resistances of the networks themselves are 1, 2, 3, and 4. So any one of the numbered resistors in these networks can be replaced by one of the networks themselves.

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