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 A245998 #8 Jul 23 2025 11:31:01 %S A245998 2,18,164,676,2262,5766,13064,25992,48170,82810,135852,212268,320894, %T A245998 468846,668432,929296,1267794,1696482,2236340,2903220,3723302,4716118, %U A245998 5913624,7339416,9031802,11018826,13345724,16045372,19170510,22759230 %N A245998 Number of length 3+2 0..n arrays with no pair in any consecutive three terms totalling exactly n. %C A245998 Row 3 of A245995 %H A245998 R. H. Hardin, <a href="/A245998/b245998.txt">Table of n, a(n) for n = 1..210</a> %F A245998 Empirical: a(n) = 3*a(n-1) -8*a(n-3) +6*a(n-4) +6*a(n-5) -8*a(n-6) +3*a(n-8) -a(n-9). %F A245998 Empirical: G.f.: 2*x*(1+6*x+55*x^2+100*x^3+183*x^4+86*x^5+49*x^6) / ( (1+x)^3*(x-1)^6 ). - _R. J. Mathar_, Aug 10 2014 %e A245998 Some solutions for n=10 %e A245998 ..6....9....2....7....1...10....9....7....9....9....3....5....1....5....5....6 %e A245998 ..8....9....7...10....4....8....8....9...10....6....9....6....5....6....8....1 %e A245998 ..3...10...10....9....3....4...10....0....3....2....2....1....2....7....3....5 %e A245998 ..6....2....5....4....2....9...10....3....2...10....4....2....1....2....5....1 %e A245998 ..3....2...10....4....9...10....6....0....9....9...10....3....7....1....8....0 %K A245998 nonn %O A245998 1,1 %A A245998 _R. H. Hardin_, Aug 09 2014