What is the supplication recited upon sighting the crescent moon of the blessed month of Ramadan?

There is no specific mention [of a supplication] upon seeing the Ramadan crescent, but what is mentioned upon seeing any crescent is what Imam Ahmad narrated: that the Prophet (peace and blessings be upon him) used to say, "O Allah, bring it upon us with Yemen (blessings), faith, safety, and Islam. My Lord and your Lord is Allah." It is also reported in Sunan Abi Dawud that when the Prophet (peace and blessings be upon him) saw the crescent, he would say, "Crescent of goodness and guidance" - three times - "I believe in the One who created you" - three times - then he would say, "Praise be to Allah who has taken away such and such a month and brought such and such a month." However, some scholars have deemed its chain of narration weak.