Residue tables

Squares, cubes and other powers mod mm at a glance.

For checking your work after you’ve tried it yourself.

Step 1:
Choose m

Any modulus from 2 to 60.

Step 2:
Choose the powers

Up to 12 columns.

Step 3:
Pick a column

See which remainders that power can and can't leave.
What it does.
Builds a table of xe mod mx^e \bmod m for every xx from 0 to m−1m - 1, so you can see at a glance which remainders squares, cubes and higher powers leave.
When it helps.
Checking a fact like "squares leave remainder 0 or 1 mod 4" before you rely on it.
What it won’t do.
Moduli up to 60 and powers up to 12.
Example.
Squares mod 8 are only 0, 1 and 4.
Powers xex^{e} mod mm

Tap a column header in the table to study that power.

Try