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 A066576 #12 Sep 08 2022 08:45:04
%S A066576 30031,510511,9699691,223092871,6469693231,7420738134811,
%T A066576 304250263527211,13082761331670031,614889782588491411,
%U A066576 32589158477190044731,1922760350154212639071,117288381359406970983271
%N A066576 Composite Euclid numbers: numbers of the form p# + 1, where p# denotes the primorial of the prime p.
%C A066576 30031 appears in Wells's "Curious and Interesting Numbers" as the smallest composite number of the form p# + 1.
%D A066576 David Wells, "The Penguin Dictionary of Curious and Interesting Numbers," Revised Edition, Penguin Books, London, England, 1997, page 166.
%H A066576 Amiram Eldar, <a href="/A066576/b066576.txt">Table of n, a(n) for n = 1..341</a>
%t A066576 Do[c = Product[ Prime[i], {i, 1, n}] + 1; If[ !PrimeQ[c], Print[c]], {n, 1, 20} ]
%o A066576 (Magma) [a: n in [2..19]| not IsPrime(a) where a is 1+&*[NthPrime(k):k in [1..n]]]; // _Marius A. Burtea_, Feb 18 2020
%Y A066576 Cf. A014545, A006862.
%K A066576 nonn
%O A066576 1,1
%A A066576 _Joseph L. Pe_, Jan 07 2002
%E A066576 Edited by _Robert G. Wilson v_, Jan 09 2002