# Combinatorial Maxima

For each positive integer n, let A$$_{n}$$=max{$$\binom{n}{r}|0 \leq r \leq n$$}. Then the number of elements in {1, 2, 3, ....., 20} for which $$1.9 \leq \frac{A_{n}}{A_{n-1}} \leq 2$$

Note:This question is a part of set KVPY 2014 SB

×