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 A159571 #4 Jun 02 2025 01:38:24 %S A159571 6,39,138,364,804 %N A159571 Fifth diagonal in Table A159572; previous diagonals are A000012, A000217, A000330 and A086602. %C A159571 The sequence can be generated by adding the below four sequences term by term: %C A159571 1...5..14...30...55.. %C A159571 3..18..60..150..315.. %C A159571 1...7..25...65..140.. %C A159571 1...9..39..119..294.. %K A159571 easy,nonn %O A159571 1,1 %A A159571 _Alford Arnold_, Apr 15 2009