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 A200151 #6 Jul 22 2025 15:41:38 %S A200151 1,6,18,66,202,730,2036,7488,19262,62772,190408,1077600,2185196, %T A200151 12081408,21927244,52980770,148851716,1353060240,2585159746, %U A200151 16942421808,28793485330,51092435876,106822624510,1565885020128 %N A200151 Number of 0..5 arrays x(0..n-1) of n elements with zero n-1st difference. %C A200151 Column 5 of A200154 %e A200151 Some solutions for n=6 %e A200151 ..4....3....3....0....4....1....5....3....0....5....5....5....5....5....4....5 %e A200151 ..4....5....3....2....4....3....3....1....1....0....3....4....1....0....0....4 %e A200151 ..1....0....4....1....0....4....3....2....3....2....4....2....2....3....3....5 %e A200151 ..1....0....3....1....0....3....3....2....2....4....5....1....3....4....4....5 %e A200151 ..4....5....1....3....4....1....3....1....0....4....5....1....3....2....2....4 %e A200151 ..4....3....3....5....4....1....5....3....5....5....5....0....5....5....4....5 %K A200151 nonn %O A200151 1,2 %A A200151 _R. H. Hardin_ Nov 13 2011