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 A308683 #21 Jul 22 2021 02:08:13 %S A308683 17042641441,180383003522,231242161921,313187053922,349881182161, %T A308683 717767333521,740230547281,907336510801,1080505860722,1646310367681, %U A308683 1682581387922,1896109379522,2638936079522,2919248012401,3121595927522 %N A308683 Numbers k such that k, k+1, k+2, k+3 are all of the form p*q^2 for distinct primes p,q. %C A308683 See StackExchange link for pseudo-code to generate four or five consecutive values of the form. %H A308683 Ray Chandler, <a href="/A308683/b308683.txt">Table of n, a(n) for n = 1..10000</a> %H A308683 StackExchange, <a href="http://math.stackexchange.com/questions/64892/sequence-of-numbers-with-prime-factorization-pq2">Sequence of numbers with prime factorization pq^2</a> %H A308683 <a href="/index/Pri#prime_signature">Index to sequences related to prime signature</a> %e A308683 17042641441 = 7 * 7 * 347809009, %e A308683 17042641442 = 2 * 92311 * 92311, %e A308683 17042641443 = 3 * 3 * 1893626827, %e A308683 17042641444 = 2 * 2 * 4260660361. %Y A308683 Cf. A054753, A074172, A178032, A141621. %K A308683 nonn %O A308683 1,1 %A A308683 _Ray Chandler_, Jun 21 2019