Śrīmad-Bhāgavatam · Text 9.15.30
Who is speaking and story frame
अचोदयद्धस्तिरथाश्वपत्तिभि-
र्गदासिबाणर्ष्टिशतघ्निशक्तिभि: ।
अक्षौहिणी: सप्तदशातिभीषणा-
स्ता राम एको भगवानसूदयत् ॥ ३० ॥
acodayad dhasti-rathāśva-pattibhir
gadāsi-bāṇarṣṭi-śataghni-śaktibhiḥ
akṣauhiṇīḥ sapta-daśātibhīṣaṇās
tā rāma eko bhagavān asūdayat
Upon seeing Paraśurāma, Kārtavīryārjuna immediately feared him and sent many elephants, chariots, horses and infantry soldiers equipped with clubs, swords, arrows, ṛṣṭis, śataghnis, śaktis, and many similar weapons to fight against him. Kārtavīryārjuna sent seventeen full akṣauhiṇīs of soldiers to check Paraśurāma. But Lord Paraśurāma alone killed all of them.
Read Śrīla Prabhupāda's purport on Vedabase.io