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Trinity1 is a puzzle to be solved with a single attempt allowed. Please send your solution to dawid.skrzos@o2.pl. Anyone who solves it will be included on the list of solvers. Participants who choose to remain anonymous will be listed as "Anonymous". The sequence follows a simple rule and shouldn't be considered a form of analogy, as it is one entity.

The puzzle:

1248163264, 357111317192329313741434753596167717379838997, 6912244896, 10??????????????????????????, 15????????????, 21????????????????