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 A187030 #8 Jul 22 2025 10:38:37 %S A187030 0,0,5120,45152,161256,376248,696992,1121176,1647008,2273384,3000304, %T A187030 3827768,4755776,5784328,6913424,8143064,9473248,10903976,12435248 %N A187030 Number of 5-step one or two collinear space at a time queen's tours on an n X n board summed over all starting positions. %C A187030 Row 5 of A187027 %F A187030 Empirical: a(n) = 50272*n^2 - 328792*n + 534104 for n>7 %e A187030 Some solutions for 4X4 %e A187030 ..0..0..0..0....0..5..0..0....0..0..4..0....0..0..0..0....0..0..0..0 %e A187030 ..0..5..0..0....0..0..0..1....0..3..0..5....1..2..0..3....0..3..5..4 %e A187030 ..0..1..2..0....0..4..3..0....0..2..0..0....5..0..0..0....0..0..2..0 %e A187030 ..0..4..3..0....0..2..0..0....1..0..0..0....0..4..0..0....0..0..0..1 %K A187030 nonn %O A187030 1,3 %A A187030 _R. H. Hardin_ Mar 02 2011