Declension table of ?saptaputra

Neuter	Singular	Dual	Plural
Nominative	saptaputram	saptaputre	saptaputrāṇi
Vocative	saptaputra	saptaputre	saptaputrāṇi
Accusative	saptaputram	saptaputre	saptaputrāṇi
Instrumental	saptaputreṇa	saptaputrābhyām	saptaputraiḥ
Dative	saptaputrāya	saptaputrābhyām	saptaputrebhyaḥ
Ablative	saptaputrāt	saptaputrābhyām	saptaputrebhyaḥ
Genitive	saptaputrasya	saptaputrayoḥ	saptaputrāṇām
Locative	saptaputre	saptaputrayoḥ	saptaputreṣu

Compound saptaputra -

Adverb -saptaputram -saptaputrāt