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 A123298 #15 Sep 04 2023 11:33:35 %S A123298 0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,4,6,18,14,26,84,88,46,176,380,812, %T A123298 844,1770,2164,5554,9244,25384,62092,68176,85762,304892,855072, %U A123298 1229050,1805096 %N A123298 Number of incongruent restricted disjoint covering systems (IRDCS) of length n. %C A123298 An IRDCS of length n is a sequence of n integers s(1),...,s(n) with the property that if s(i)=m for some m then the other terms of the sequence with value m are precisely s(i+k*m) for all k such that i+k*m is in [1,n] and further such that any integer appearing in the sequence appears at least twice. For example, the two IRDCS of length n are 6,9,3,4,5,3,6,4,3,5,9 and its reverse. %D A123298 Gerry Myerson, Jacky Poon and Jamie Simpson, Incongruent restricted disjoint covering systems, preprint. %K A123298 nice,nonn %O A123298 1,11 %A A123298 _Jamie Simpson_, Jun 25 2007, corrected Sep 11 2007