Formal languages: What is $2n_c$?
This language is not CFL.

Consider the language $L \cap a^*b^*c^*$ . Assume that $L$ is CFL, now, as $ a^*b^*c^*$ is regular and CFL are closed under intersection with regular languages, $L \cap a^*b^*c^*$ would be CFL. But $L \cap a^*b^*c^* = a^nb^nc^{2n}$, which is not context free (The proof is similar to this). Hence the contradiction!

Thus the given language is not CFL.