228921, because if the function f(x) is defined as follows:
-11597x⁵/6+100285x⁴/3-416905x³/2+1766885x²/3-2247644x/3+337211
then:
f(1) = 1
f(2) = 11
f(3) = 21
f(4) = 1211
f(5) = 111221
f(6) = 312211
f(7) = 228921