Coefficient of certain power of variable in binomial

Sum of the last 30 coefficients of powers of x in the binomial expansion of (1 + x)^(59) is:

Sum of binomial coefficients odd binomial coefficients even binomial coefficients

Properties OF binomial coefficient ,questions on properties OF binomial coefficient

the coefficient of the middle term in the binomial expansion , in power of x, of (1 + ax)^(4) and of ( 1 + ax)^(6) is same, of a equal .

What is the coefficient of the middle term in the binomial expansion of (2+3x)^(4) ?