What data type are the analog pin labels (A0, A1, etc)?
As you can see in Arduino.h, the analogRead() has uint8_t as parameter. You can define them as byte or uint8_t and you don't have to use the sizeof().

The type of A0 is defined in the file pins_arduino.h:

#define PIN_A0 (14)
static const uint8_t A0 = PIN_A0;


Nevertheless, what you have with integers is 100% okay as well.

When you don't have a Arduino board available, you can use the simulation of an Arduino Uno at Tinkercad.



As @DataFiddler writes below this answer, using a 'const' keyword is preferred:

const uint8_t analog_pins[] = {A0, A1, A2, A3};