Practical impact would be:
-2 CA
-1 TX, FL, IL
+1 UT, ID, WV, DE, SD
Surprisingly less than I expected.
For other methods you need to calculate a different quota. The only way I know to do that is recursively.
S0 = 435
For Jefferson's method begin with the quota of 801,000 (or Q = PUSA/S0 = 435, and determine an apportionment entitlement for each state Ei = Pi/Q - 1 these should sum to S1 = 385.
Calculate a new quota Qi+1 = PUSA/( Si / Si-1 )
This will produce a smaller quota, which when calculating entitlement will sum closer to 435. Iterate until this converges.
Compare the entitlement between the two methods.
You can also use "priority values", having a multiplier for the
nth seat a state would be awarded as a function of
n (for the Adams method, that multiplier would be 1/(
n − 1), or
n − 1 would be the divisor), multiplying each of those multipliers (or more than enough for each state) by each state's population and then starting with 1 seat for each state and awarding seats to the top
435 − 50 = 385 entries (or you could think of the multipliers for the first seat (where you would have to divide by 1 − 1 =
1 0) being (positive) infinity (∞), so you'll have 50 infinites, then California's whole population (which earns it a second seat as the 51st seat in the U.S. House), then Texas's, then Florida's, then New York's, then California's population divided by 2 (so seat #55 is California's third seat), and so on).
I'm explaining this somewhat lazily here. But this heuristic can be useful if you're making a spreadsheet to calculate multiple potential apportionments (either changing the apportionment method or changing the number of seats) and not wanting to have to adjust the divisor each time.
There's a continuum of methods where the cutoff or "signpost" (in the heuristic where a state has to get to or past a certain real number (often not an integer) "signpost" to get n seats and the divisor is adjusted until you get the right total number of seats) or the divisor (in the heuristic assign a "priority value" for each state getting an
nth seat for each
n) is a
generalized or power mean of the number of seats the state would already have at this point and the seat it is "going for". It's a complex looking formula, which errors out at 0 and at positive and negative infinities, but using the mathematical concept of limits and substituting the limits where the function would error out you can get values for all real numbers, including ∞ and −∞. The Adams method, sometimes called the method of "Smallest Divisors" (although in the "adjust the divisor by trial and error" method the divisor needed to get a certain number of seats would be the highest of any of the methods on this continuum; in the "priority value" method the divisors are indeed the smallest), corresponds to
p = −∞. The first method used, Jefferson's or "Greatest Divisors", corresponds to
p = ∞. Our current method of Equal Proportions or Huntington-Hill, which has been used from 1941 on, corresponds to
p = 0 (the geometric mean). Major Fractions or Webster's method, used in the apportionments following the 1840, 1910 and 1930 censuses, uses the arithmetic mean (the mean you probably learned in grade school) of the two adjacent seat numbers, which is the variant of the power mean where
p = 1.
[Edited to correct a math error and one instance where I left off one side of an expression.]