Ferdinand Georg Frobenius, new giant of the 'week'.

I cannot have enough of Grigory Perelman's picture, but people have been complaining: the meaning of 'week' is being undeservedly stretched.

The new giant, with the mandatory beard, is Ferdinand Georg Frobenius.

I stumbled upon him during week 16, more specifically, while reading about the amazing history of the Grandi series, where you will find Frobenius at the last paragraph of: http://en.wikipedia.org/wiki/History_of_Grandi's_series