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 A373560 #9 Jun 10 2024 14:56:53 %S A373560 -1,-1,-1,10093613546512321,-1,-1,7700031346933907521,-1, %T A373560 5344962129269790721,-1,20453982425165652721,-1,8163195338222675521, %U A373560 -1,2467958104789157112721,-1,-1,-1,-1,14666767069023896053921,212170739123852995921,287954235303137500060321,-1,84769922583214545304321 %N A373560 a(n) is the smallest multiple of prime(n)^2 that starts a run of 5 consecutive integers with 6 divisors, or -1 if no such multiple exists. %C A373560 Terms were obtained using the b-file at A141621. %C A373560 a(n) = -1 if prime(n) is not in A001132. %C A373560 Conjecture: the converse is also true. %e A373560 a(1) = a(2) = a(3) = -1 because the first of five consecutive integers having six divisors is never a multiple of 2^2, 3^2, or 5^2. %e A373560 a(4) = 10093613546512321 because it is the smallest term in A141621 that is a multiple of prime(4)^2 = 49. %e A373560 a(9) = 5344962129269790721 because it is the smallest term in A141621 that is a multiple of prime(9)^2 = 23^2. %Y A373560 Cf. A001132, A030515, A042999, A054753, A141621. %K A373560 sign %O A373560 1,4 %A A373560 _Jon E. Schoenfield_, Jun 09 2024