The Great Courses Plus (free trial): http://ow.ly/C3FE30hIvhc
This video features Dr James Grime.
More James Grime on Numberphile: http://bit.ly/grimevideos
James Grime: http://singingbanana.com
Tackling the Minimal Superpermutation Problem: https://arxiv.org/abs/1408.5108
(Apparently I mucked up the copy/paste for the 1-6 superpermutation and, amazingly, people actually check this stuff... The full number is in the paper linked above)