Mukasir sahib Syyedi Khan Ji Pheer r.z. has quoted the 19th Dai Mutlak Syyedna Idris Imamuddin a.q. and gave below names of Imams in the progeny of the 21st Imam Ameer al Mumineen Imam Tayyeb a.s. -

Count #	Name of the Imams in progeny of Imam Tayyeb a.s.
22nd Fatimi Imam	Ameer al Mumineen Imam Ahmad a.s.
23rd Fatimi Imam	Ameer al Mumineen Imam ​​Mohammad a.s.
24th Fatimi Imam	Ameer al Mumineen Imam Abdullah a.s.
25th Fatimi Imam	Ameer al Mumineen Imam Hussain a.s.
26th Fatimi Imam	Ameer al Mumineen Imam Ma'ad a.s.
27th Fatimi Imam	Ameer al Mumineen Imam Nizaar a.s.
28th Fatimi Imam	Ameer al Mumineen Imam Hashim a.s.
29th Fatimi Imam	Ameer al Mumineen Imam Mohammad a.s.
30th Fatimi Imam	Ameer al Mumineen Imam  Ali a.s.

Book "Wazkur Fil Kitaab Ismail" on page # 25 has quoted some book that give names of approx. 20 Imams following the Imam Tayyeb a.s. -
 
1. Ahmad, 2. Mohammad, 3. Abdullah, 4. Mohammad, 5. Ali, 6. Hussain, 7. Ma'ad, 8. Nizaar, 9. Hashim, 10. Mohammad, 11. Ali, 12. Abu Talib, 13. Ali, 14. Ahmad, 15. Ali, 16. Ismail, 17. Ma'ad, 18. Hasan, 19. Mohammad, 20. Ahmad, 21. Ali (salwaat & salam on all).

Note: An Imam can be known by his name as well as his Quniya or can be known with another name / alias. 

Prophecy of Imam Jaffer Sadiq a.s. - Case of Sardar Tahir Saifuddin and Sheikh Ahmed Ali Raj -

Sheikh Ahmed Ali Raj sahib approached Sardar Tahir Saifuddin (contender of 51st Dai Mutlak) and inquired: In our Fatimi Dawat literature it is written that Imam Jaffer al Sadiq a.s. has said, "In city of Mecca, next to the Kaaba, where 'Sahi' is done - this place which throngs lots of shops and houses will be all-cleared by a rightful Imam in the times ahead." Now I have seen that after arrival of Saud (the king of Saudi Arabia) this time this place is all clear from all shops and houses. So should we regard him as Imam? No, because they are hardcore enemy of the Ahlul Bayt!!!

Sardar Tahir Saifuddin sahib called Sheikh Ahmed Ali Raj in privacy and replied - The place of Sahi is not entirely clear of all shops and houses. So when it will be completely clear then the prophecy of Imam Jaffer Sadiq will materialize and that will be done by an Imam. 

Sheikh Ahmed Ali sahib in person was witness that the matter of fact is that that place is entirely clear with all shops and houses, and not partially. (This can be vouched even today by those who go for Haj and Umra that the place of sahi is clear of all shops and houses.

Sheikh Ahmed Ali sahib thirst for right answer was quenched by Martyr Al Alim ur Rashid Sheikh Sajjad Hussain Sarangpur wala sahib. Later told to former - The hands of Imam (the dai's and servants of Imams) in undercover form are present in world's all important parliaments and places, those undercover Fatimi dai's were present in the parliament of Saud as well and they have motivated Saud to clear the path of 'Sahi' from all houses and shops. Dai's receive command from Imam of time. So those removal though was done apparently by Saud but was handwork of Fatimi Imam a.s. of time. 

The point to note is: Though we may or may not have direct access to the Imam but they do their job always. The prophecy of Imam Jaffer Sadiq a.s. is proof that Fatimi Imam was, is, and will always be present.  Salwaat. 

Aga Khani historian Farhad Daftry and Bohra Aalim Sheikh al Fazil Chand Khan Ji Rampura wala in their books have wrote that Imam-uz-zaman wrote letters to Sardar Najmuddin sahib (after the martyrdom of last 46th dai Syyedna Mohammad Badruddin a.q.) to hand the leadership of Dawat to Mazoon sahib Syyedi Jamaluddin sahib r.z. (who was mazoon of Shaheed Dai Mohammad Badruddin a.q.) .