Let 1,2,3,…,2005,2006,2007,2009,2012,2016,… be a sequence defined by xk=k for k=1,2…,2006 and xk+1=xk+xk−2005 for k≥2006. Show that the sequence has 2005 consecutive terms each divisible by 2006. Putnamvectorlinear algebramatrixmodular arithmeticcollege contests