Constraint about encrypted values
To capture value/position relations, a "sequence polynomial representation" was suggested, in the context of proving properties of DNA. Self-citing: IACR preprint 2008/357. This technique could apply here in case of ElGamal ciphertext, that could be proven with Schnorr-like responses. The major idea remains to re-state "consecutive" as a property of "characteristic polynomial", that (I believe) is doable. Hamiltonicity test (2008/363) could be another example.