Such were the locksmith’s thoughts when first seated in the snug corner, […] — (Charles Dickens, Barnaby Rudge)
This is referred to as linear growth because the number of recursive calls is directly proportional to the value of the argument provided when the function is first called. — (Ben Stephenson, The Python Workbook , (2nde édition), Springer, 2019, lêmbëtï 131)