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 A288030 #18 May 29 2025 10:40:18 %S A288030 1,6,38,190,1021,5494,29042,154772,824695,4386942,23356322,124344111, %T A288030 661873859,3523418150,18756407661,99845472493,531509598443, %U A288030 2829393615575,15061734439895,80178331797652,426814323111204,2272065745374039,12094915689644237 %N A288030 Number of minimal edge covers in the grid graph P_3 X P_n. %H A288030 Andrew Howroyd, <a href="/A288030/b288030.txt">Table of n, a(n) for n = 1..200</a> %H A288030 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>. %H A288030 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MinimalEdgeCover.html">Minimal Edge Cover</a>. %F A288030 Empirical: a(n) = 3*a(n-1)+6*a(n-2)+35*a(n-3) -7*a(n-4)+15*a(n-5)-55*a(n-6) +31*a(n-7)+36*a(n-8)+36*a(n-9) -124*a(n-10)-8*a(n-12)+32*a(n-13) +a(n-14)+9*a(n-15)-2*a(n-16) -2*a(n-17)-a(n-18) for n>18. %F A288030 Empirical g.f.: x*(1 + 3*x + 14*x^2 + 5*x^3 + 20*x^4 - 12*x^5 + 15*x^6 + 6*x^7 + 2*x^8 - 82*x^9 - 5*x^10 - 3*x^11 + 29*x^12 + 8*x^14 - 2*x^15 - 2*x^16 - x^17) / (1 - 3*x - 6*x^2 - 35*x^3 + 7*x^4 - 15*x^5 + 55*x^6 - 31*x^7 - 36*x^8 - 36*x^9 + 124*x^10 + 8*x^12 - 32*x^13 - x^14 - 9*x^15 + 2*x^16 + 2*x^17 + x^18). - _Colin Barker_, Jun 16 2017 %Y A288030 Row 3 of A288025. %Y A288030 Cf. A288029, A288027. %K A288030 nonn %O A288030 1,2 %A A288030 _Andrew Howroyd_, Jun 04 2017