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 A268780 #6 May 04 2021 15:33:02 %S A268780 72,766,10615,115391,1288693,13493468,140404442,1425678976, %T A268780 14341399141,142487073304,1404716302427,13742060955231, %U A268780 133640514636584,1292631496259982,12446235637750465,119353876258739189 %N A268780 Number of n X 7 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two no more than once. %C A268780 Column 7 of A268781. %H A268780 R. H. Hardin, <a href="/A268780/b268780.txt">Table of n, a(n) for n = 1..210</a> %F A268780 Empirical: a(n) = 12*a(n-1) +64*a(n-2) -942*a(n-3) -1476*a(n-4) +26868*a(n-5) +2249*a(n-6) -376788*a(n-7) +333472*a(n-8) +2686292*a(n-9) -4376424*a(n-10) -8985248*a(n-11) +21881197*a(n-12) +12658940*a(n-13) -55768960*a(n-14) +923990*a(n-15) +80699088*a(n-16) -25850884*a(n-17) -69171189*a(n-18) +34934900*a(n-19) +34833816*a(n-20) -22502076*a(n-21) -9502460*a(n-22) +7752808*a(n-23) +1023260*a(n-24) -1356480*a(n-25) +55136*a(n-26) +94080*a(n-27) -14400*a(n-28). %e A268780 Some solutions for n=4 %e A268780 ..0..0..0..0..1..0..0. .0..1..0..0..0..0..0. .1..0..1..0..0..1..0 %e A268780 ..0..0..0..0..0..0..0. .0..0..0..1..0..1..0. .0..0..0..0..0..0..1 %e A268780 ..0..0..0..0..1..0..0. .0..0..0..0..0..0..0. .1..0..0..0..0..0..0 %e A268780 ..0..0..0..1..0..0..0. .1..0..0..0..0..0..1. .0..0..0..0..0..0..1 %Y A268780 Cf. A268781. %K A268780 nonn %O A268780 1,1 %A A268780 _R. H. Hardin_, Feb 13 2016