Outrageously Funny Word Dictionary :: Thirteenthly

👉 In mathematics, "thirteenthly" refers to a number that is one less than a multiple of 13. This can be represented as follows: $$ \text{Thirteenthly} = 12 - 13 $$ So in the context of an arithmetic sequence or progression, it represents the thirteenth term when starting from the first term (a) and counting by one each time to get to a given term (b).

thirteenthly