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 A238592 #18 May 29 2017 21:11:17 %S A238592 1,4,9,2,1,4,18,8,1,8,42,28,1,8,77,165,151,44,6,1,12,133,521,891,543, %T A238592 106,1,12,200,1160,3022,2756,824,1,16,288,2260,8443,13336,9364,2819, %U A238592 387,20,1,16,387,3867,19833,48418,58731,34797,9462,900 %N A238592 Number T(n,k) of equivalence classes of ways of placing k 3 X 3 tiles in an n X 10 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=3, 0<=k<=3*floor(n/3), read by rows. %H A238592 Andrew Howroyd, <a href="/A238592/b238592.txt">Table of n, a(n) for n = 3..989</a> %H A238592 Christopher Hunt Gribble, <a href="/A238009/a238009_1.cpp.txt">C++ program</a> %e A238592 The first 6 rows of T(n,k) are: %e A238592 .\ k 0 1 2 3 4 5 6 %e A238592 n %e A238592 3 1 4 9 2 %e A238592 4 1 4 18 8 %e A238592 5 1 8 42 28 %e A238592 6 1 8 77 165 151 44 6 %e A238592 7 1 12 133 521 891 543 106 %e A238592 8 1 12 200 1160 3022 2756 824 %o A238592 (C++) See Gribble link. %Y A238592 Cf. A034851, A226048, A102541, A226290, A238009, A228570, A225812, A238189, A238190, A228572, A228022, A231145, A231473, A231568, A232440, A228165, A238550-A238552, A228166, A238555, A238556, A228167, A238557-A238559, A228168, A238581-A238583, A228169, A238586. %K A238592 tabf,nonn %O A238592 3,2 %A A238592 _Christopher Hunt Gribble_, Mar 01 2014 %E A238592 Terms corrected and xrefs updated by _Christopher Hunt Gribble_, Apr 27 2015 %E A238592 Terms a(36) and beyond from _Andrew Howroyd_, May 29 2017