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 A098166 #21 May 22 2022 14:31:55
%S A098166 2,4,5,6,7,10,9,14,13,21,17,15,24,19,21,28,24,26,31,25,23,24,25,54,32,
%T A098166 30,36,56,54,48,41,77,60,36,45,40,52,51,43,48,48,62,108,62,88,49,64,
%U A098166 74,55,63,65,111,69,66,63,123,91,66,83,92,97,110,67,75,99,87
%N A098166 a(n) is the prime index of the Lesser Fortunate number A055211(n), or 0 if A055211(n) is not a prime.
%H A098166 Jinyuan Wang, <a href="/A098166/b098166.txt">Table of n, a(n) for n = 2..2000</a>
%H A098166 Antonín Čejchan, Michal Křížek, and Lawrence Somer, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL25/Krizek/krizek3.html">On Remarkable Properties of Primes Near Factorials and Primorials</a>, Journal of Integer Sequences, Vol. 25 (2022), Article 22.1.4.
%F A098166 a(n) = A000720(A055211(n)) iff A055211(n) is a prime. - _Michel Marcus_, Oct 05 2019
%o A098166 (PARI) a(n) = {my(k = prod(j=1, n, prime(j))); p = k-precprime(k-2); if(isprime(p), primepi(p), 0); } \\ _Jinyuan Wang_, Oct 02 2019
%Y A098166 Cf. A000720, A055211, A098167.
%K A098166 nonn
%O A098166 2,1
%A A098166 _Pierre CAMI_, Aug 30 2004
%E A098166 Name edited by and more terms from _Jinyuan Wang_, Oct 02 2019