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 A207602 #7 Jul 22 2025 20:37:50 %S A207602 10,100,270,729,3915,21025,75400,270400,1223560,5536609,21791133, %T A207602 85766121,366828210,1568952100,6380972950,25951599025,108806945995, %U A207602 456193527241,1877616346320,7727955206400,32166490458960,133888341846169 %N A207602 Number of 5Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically. %C A207602 Row 5 of A207599 %H A207602 R. H. Hardin, <a href="/A207602/b207602.txt">Table of n, a(n) for n = 1..210</a> %F A207602 Empirical: a(n) = a(n-1) -4*a(n-2) +21*a(n-3) +149*a(n-4) +124*a(n-5) +680*a(n-6) -2720*a(n-8) -1984*a(n-9) -9536*a(n-10) -5376*a(n-11) +4096*a(n-12) -4096*a(n-13) +16384*a(n-14) %e A207602 Some solutions for n=4 %e A207602 ..1..1..1..1....1..1..0..0....0..1..1..1....1..1..1..0....1..1..1..1 %e A207602 ..1..1..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..1 %e A207602 ..1..1..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..0 %e A207602 ..1..1..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..0 %e A207602 ..1..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..0 %K A207602 nonn %O A207602 1,1 %A A207602 _R. H. Hardin_ Feb 19 2012