Which item below is the odd one out?

A odd # is 3.5.7 and etc such that you have odd numbers

lancelot said to the beautiful ellen i c u r a b u t l n (i see you are a beauty lancelot was the greatest and worst of the knights who became the king's champion and undertook quests in the king's name. he became the adulterous lover of queen guinevere, and they had a son named galahad.