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 A381893 #19 Mar 19 2025 10:38:38 %S A381893 -810,-39184,-4396135,-124970,-61325522,-64927344,-439288021 %N A381893 Negative values of A381781. %F A381893 a(n) = A381781(A381892(n)). %e A381893 A381781(99) = -810. %Y A381893 Cf. A381781, A381892. %K A381893 sign,hard,more %O A381893 1,1 %A A381893 _Simcha Z. Katzoff_, Mar 09 2025