  Motivated by the works of Krasner [arXiv:0801.4018] and Lobb
[arXiv:1103.1412], we simplify the Khovanov-Rozansky chain complexes of open
2-braids. As an application, we show that, for a knot containing a "long"
2-braid, the sl(N) Rasmussen invariant of this knot depends linearly on the
length of this 2-braid. We refine this result for (2,2k+1) cable knots and, as
a simple corollary, compute the sl(2) Rasmussen invariants of (2,2k+1) cables
of slice and amphicheiral knots.
