Artist making mathematical sculptures

There is an online encyclopaedia of integer sequences. I have to mull this over in my head for a while.

" ... Street-Fighting Mathematics — the title refers to the fact that in a street fight, it’s better to have a quick and dirty answer than to stand there thinking about the right thing to do — is based on the premise that we can and should use rapid estimation techniques to get rough answers to difficult problems. There are good reasons for preferring estimation over rigorous methods: the answer is arrived at quickly, the full set of input data may not be needed, and messy calculus-based or numerical techniques can often be avoided. Perhaps more important, by avoiding a descent into difficult symbol pushing, a greater understanding of the problem’s essentials can sometimes be gained and a valuable independent check on rigorous — and often more error prone — methods is obtained. ... "

"... If you’re into signal processing, you will no doubt say that the headline is a very tall claim. I would second this. Of course you can’t learn all the bells and whistles of the Fourier transform in one day without practising and repeating and eventually delving into the maths. ..."