This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A056756 #8 May 05 2022 16:26:34
%S A056756 1,2,7,3,12,5,13,36,25,33,50,18
%N A056756 Where n-th prime appears in Euclid-Mullin sequence A000945.
%t A056756 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 A056756 Cf. A000945.
%K A056756 nonn,hard,more
%O A056756 1,2
%A A056756 _Robert G. Wilson v_, Aug 15 2000
%E A056756 Gaps that need filling: 1, 2, 7, 3, 12, 5, 13, 36, 25, 33, 50, 18, ?, 4, ?, 6, ?, 42, ?, 22, ?, ?, ?, 35, 26
%E A056756 Two more terms from _Sean A. Irvine_, Sep 20 2012