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 A120120 #15 Oct 28 2021 13:06:09
%S A120120 1,3,7,26,128,733,3869,23620,152141,1028789,7188960,51672312,
%T A120120 381226246,2873279651
%N A120120 Number of n-digit prime quadruplets.
%H A120120 J.-L. Baril, <a href="http://www.combinatorics.org/ojs/index.php/eljc/article/view/v18i1p178">Classical sequences revisited with permutations avoiding dotted pattern</a>, Electronic Journal of Combinatorics, 18 (2011), #P178.
%H A120120 Thomas R. Nicely, <a href="https://faculty.lynchburg.edu/~nicely/quads/quads.html">Enumeration to 1.6*10^15 of the prime quadruplets</a>.
%e A120120 a(3) = 3 because there are three three-digit prime quadruples: {101, 103, 107, 109}, {191, 193, 197, 199} and {821, 823, 827, 829}.
%Y A120120 Cf. A006879, A070076, A038801.
%K A120120 nonn,more,base
%O A120120 2,2
%A A120120 Julien Peter Benney (jpbenney(AT)ftml.net), Aug 15 2006, Aug 19 2006
%E A120120 a(6) corrected and a(15) supplied by _Jon E. Schoenfield_, Aug 27 2006