- Use exponentiation in `euler_polynomial(n,x)` and `bernoulli_polynomial(n,x)` for computing "x^k", as it seems to be faster than using repeated multiplication.
- Use exponentiation in `euler_polynomial(n,x)` and `bernoulli_polynomial(n,x)` for computing "x^k", as it seems to be faster than using repeated multiplication.

trizen/sidef,trizen/sidef,trizen/sidef,trizen/sidef