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 A183266 #7 May 12 2020 19:57:00 %S A183266 120,3552,57064,681984,6849792,61486080,511006848,4019699712, %T A183266 30364991488,222472642560,1592011745280,11183547482112,77409364082688, %U A183266 529414815744000,3585105638490112,24077527815290880,160571745918517248,1064387288330403840,7018456956044574720 %N A183266 Number of singly defective permutations of 1..n+4 with exactly 3 maxima. %C A183266 A singly defective permutation omits one value and repeats another value. %H A183266 Andrew Howroyd, <a href="/A183266/b183266.txt">Table of n, a(n) for n = 1..200</a> %e A183266 Some solutions for n=3 with 3 maxima: %e A183266 (2,5,3,4,3,1,7) (2,1,7,4,3,6,2) (4,2,6,5,7,4,3) (4,3,3,7,2,5,1). %Y A183266 Column 3 of A183270. %K A183266 nonn %O A183266 1,1 %A A183266 _R. H. Hardin_, Jan 03 2011 %E A183266 Terms a(12) and beyond from _Andrew Howroyd_, May 12 2020