WordNet records no synonym and no antonym for arithmetic progression. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(mathematics) a progression in which a constant is added to each term in order to obtain the next term
“1-4-7-10-13- is the start of an arithmetic progression”
Synonyms, antonyms and the broader and narrower relations for arithmetic progression come from Princeton University’s WordNet. Full sources and licences.