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 A131997 #5 Feb 20 2019 05:34:43 %S A131997 1,3,9,27,15,81,243,45,729,2187,135,105,6561,225,19683,405,59049, %T A131997 177147,1215,315,675 %N A131997 Array read by rows in which the n-th row contains odd numbers of all possible prime signatures with n divisors. %e A131997 Row 12 of A131886 is 2048 96 72 60 so here row 12 is 177147 1215 315 675. %Y A131997 Cf. A001055, A025487, A050322, A057567, A077569, A108464, A122819, A130839, A131802, A131886. %K A131997 nonn,tabf,more %O A131997 1,2 %A A131997 _Alford Arnold_, Aug 18 2007