The number of odd entries in a row of Pascal's triangle is always a power of 2. These are either equally split between 1 and 3 mod 4, or are all 1 mod 4. Similarly, for every odd
a, the number of entries in a given row of Pascal's trinagle that are
≡a(mod8) is either 0 or a power of 2. We develop a theory to explain this.
Article, Corrigendum