%I #8 May 05 2022 16:26:34
%S 1,2,7,3,12,5,13,36,25,33,50,18
%N Where n-th prime appears in Euclid-Mullin sequence A000945.
%t f[1]=2; f[n_] := f[n] = FactorInteger[Product[f[i], {i, 1, n - 1}] + 1][[1, 1]] ems = Table[f[n], {n, 1, 43}]; Do[Print[Position[ems, Prime[n]][[1, 1]]], {n, 1, 25}]
%Y Cf. A000945.
%K nonn,hard,more
%O 1,2
%A _Robert G. Wilson v_, Aug 15 2000
%E Gaps that need filling: 1, 2, 7, 3, 12, 5, 13, 36, 25, 33, 50, 18, ?, 4, ?, 6, ?, 42, ?, 22, ?, ?, ?, 35, 26
%E Two more terms from _Sean A. Irvine_, Sep 20 2012