"Charlie's not your conventional mathematician... we sexed him up a little bit"

In this quote, David Krumholtz is referring to the character of Charlie in the television program "Numb3rs." He is saying that Charlie is not a normal mathematician, implying he does not fit the stereotype of being dull or uncool. Instead, they have actually made him more appealing and intriguing, or "sexed him up." This could mean they have offered him a more enticing appearance or character, or possibly they have actually included some romantic or sexual components to his character. Overall, Krumholtz is highlighting the fact that Charlie is not simply a one-dimensional mathematician, but a dynamic and interesting character.