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 A291634 #17 May 10 2025 16:13:15 %S A291634 1,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,8,1,11,1,1,2,20,1,1,2,1,1 %N A291634 Number of primitive sequences n = b_1 < b_2 < ... < b_t = A006255(n) such that b_1*b_2*...*b_t is a perfect square. %C A291634 A primitive sequence is one such that no proper, nonempty subsequence has a product that is a perfect square. %C A291634 Trivially, a(n) <= A259527(n). If A259527(n) = 1, then a(n) = 1. %e A291634 For n = 22 the a(22) = 2 solutions are: %e A291634 22 * 24 * 33 = 132^2, and %e A291634 22 * 27 * 32 * 33 = 792^2. %e A291634 Note that 22 * 24 * 25 * 33 = 660^2 is not a solution because the subsequence [25] has a square product. %Y A291634 Cf. A006255, A259527. %K A291634 nonn,more %O A291634 1,11 %A A291634 _Peter Kagey_, Aug 29 2017