arithmetic progression

WordReference Random House Unabridged Dictionary of American English © 2026

arithmet′ic progres′sion, 

1. Mathematics a sequence in which each term is obtained by the addition of a constant number to the preceding term, as 1, 4, 7, 10, 13, and 6, 1, -4, -9, -14. Also called ar′ithmet′ic se′ries. 

• 1585–95

Collins Concise English Dictionary © HarperCollins Publishers::

arithmetic progression noun

1. a sequence of numbers or quantities, each term of which differs from the succeeding term by a constant amount, such as 3,6,9,12
   Compare geometric progression