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 A254213 #10 Nov 03 2023 15:40:01 %S A254213 2,0,3,4,8,6,15,18,45,118,553,1706,2845,2970,4470,9426,30908,115084, %T A254213 350693,804152,1724453,3598260,6467166,12292306,36973565,137754308, %U A254213 493838258,1570992174,4107583256,8556975584,14790344176,23129972292 %N A254213 Number of length n 1..(3+2) arrays with no leading or trailing partial sum equal to a prime and no consecutive values equal. %H A254213 Alois P. Heinz, <a href="/A254213/b254213.txt">Table of n, a(n) for n = 1..150</a> (first 34 terms from R. H. Hardin) %e A254213 All solutions for n=4: %e A254213 ..1....1....4....1 %e A254213 ..3....5....2....3 %e A254213 ..2....3....3....5 %e A254213 ..4....1....1....1 %Y A254213 Column k=3 of A254218. %K A254213 nonn %O A254213 1,1 %A A254213 _R. H. Hardin_, Jan 26 2015