{"schema":"vela.problem-packet.v0.1","problem":398,"statement":"Are the only solutions to\\[n!=x^2-1\\]when $n=4,5,7$?","status":"open","seam":"raw","closureRoutes":[],"obligations":[],"attestations":[],"attempts":[],"velaLean":[],"oeis":[{"id":"A141399","name":"Positive integers k such that the distinct primes that divide k or k+1 form a set of consecutive primes. In other words, k is included if and only if k*(k+1) is contained in sequence A073491.","terms":"1,2,3,5,8,9,14,15,20,24,35,80,125,224,384,440,539,714,1715,2079,2400,3024,4374,9800,12375,123200,194480,633555","url":"https://oeis.org/A141399"},{"id":"A146968","name":"Brocard's problem: positive integers n such that n!+1 = m^2.","terms":"4,5,7","url":"https://oeis.org/A146968"}],"generated_note":"derived view; the signed event log is the source of truth (vela check / vela reproduce)"}