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 A207096 #7 Jun 02 2025 07:40:19 %S A207096 5,15,45,140,441,1382,4322,13511,42238,132051,412840,1290698,4035218, %T A207096 12615643,39441343,123308779,385510576,1205254047,3768086810, %U A207096 11780485818,36830320820,115145720853,359989724116,1125466066030,3518638952555 %N A207096 Number of 0..4 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 5. %C A207096 Column 4 of A207100 %H A207096 R. H. Hardin, <a href="/A207096/b207096.txt">Table of n, a(n) for n = 1..210</a> %F A207096 Empirical: a(n) = 3*a(n-1) +a(n-2) -2*a(n-3) +a(n-5) +2*a(n-8) -a(n-10) +3*a(n-11) -2*a(n-12) +a(n-13) -a(n-14) -2*a(n-15) +a(n-16) -2*a(n-17) +a(n-19) -3*a(n-21) +a(n-25) %e A207096 Some solutions for n=5 %e A207096 ..1....0....1....2....0....0....0....2....1....3....1....0....2....4....1....1 %e A207096 ..3....0....4....3....4....0....1....3....3....3....2....2....4....4....4....4 %e A207096 ..4....1....1....2....4....2....4....4....4....2....3....4....2....3....1....4 %e A207096 ..4....3....2....4....3....4....1....3....2....3....2....3....3....2....0....3 %e A207096 ..3....4....4....4....2....1....2....3....2....1....0....2....0....4....1....2 %K A207096 nonn %O A207096 1,1 %A A207096 _R. H. Hardin_ Feb 15 2012