x = φ | x € (R\Q)

x = 1/2 | x € (Q\Z)

x = -1 | x € (Z\N)

x = 385 | x € (N)

385 is somehow a subconsciuosly remarkable number for me: If I try to come up with a random number with three or more digits, 385 is bound to show up, with the number numbers probably in that order, though it has some variation. 7 will also spring up at some point alongside those three numbers.

Other favourites: 1/(1+1/(1+1/(1+1/(...))))