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 A077621 #10 Mar 28 2025 04:20:35 %S A077621 6,10,26,30,51,66,70,78,102,122,130,154,165,174,177,182,190,210,222, %T A077621 238,246,266,273,282,285,291,310,318,330,345,357,362,366,370,390,399, %U A077621 406,418,426,429,438,455,462,483,510,518,530,533,534,546,555,561,570 %N A077621 Squarefree numbers occurring more than once in A076734. %C A077621 Primorials are a subsequence, see A077622. %H A077621 Amiram Eldar, <a href="/A077621/b077621.txt">Table of n, a(n) for n = 1..10000</a> %F A077621 A077618(a(n)) > 1. %Y A077621 Cf. A002110, A005117, A076734, A077618, A077619, A077620, A077622. %K A077621 nonn %O A077621 1,1 %A A077621 _Reinhard Zumkeller_, Nov 12 2002