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 A144722 #16 Jun 18 2021 12:21:06
%S A144722 2,3,4,6,8,21,23,26,30,36,37,39,42,54,57,73,83,86,88,91,93,98,99,112,
%T A144722 120,137,140,142,148,161,162,169,171,174,179,237,247,294,312,335,340,
%U A144722 382,474,475,484,498,500,539,589,598,653,654,660,704,720,732,789,804
%N A144722 a(n) is the smallest positive integer m such that b * (Product_{k=1..n} a(k)) + 1 is prime, with b = 3.
%e A144722 3*1+1=4 is not prime (omitted).
%e A144722 a(1)=2 because 3*2+1=7 is prime.
%e A144722 a(2)=3 because 3*2*3+1=19 is prime.
%t A144722 k = 3; a = {}; Do[If[PrimeQ[k*n + 1], k = k*n; AppendTo[a, n]], {n, 1, 3000}]; a
%Y A144722 Cf. A046966, A046972, A144717, A144718, A144723, A144724, A144725, A144726, A144727, A144728, A144729, A144730, A144731.
%K A144722 nonn
%O A144722 1,1
%A A144722 _Artur Jasinski_, Sep 19 2008
%E A144722 Definition corrected by _Georg Fischer_, Jun 18 2021