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 A254214 #5 Jul 23 2025 14:33:17 %S A254214 3,2,11,22,56,136,383,1070,3897,13372,36290,91998,263764,898044, %T A254214 3423582,12431962,40311611,119109004,342803738,1087179458,4009074487, %U A254214 15810174070,60200487014,208013211868,641452364953 %N A254214 Number of length n 1..(4+2) arrays with no leading or trailing partial sum equal to a prime and no consecutive values equal. %C A254214 Column 4 of A254218 %e A254214 Some solutions for n=4 %e A254214 ..1....1....1....4....4....4....6....4....4....6....1....4....1....6....1....6 %e A254214 ..5....5....3....2....5....6....3....2....6....4....5....6....5....4....3....4 %e A254214 ..3....6....2....6....3....5....5....3....2....2....3....2....4....6....5....5 %e A254214 ..6....4....4....4....6....1....4....1....6....6....1....4....6....4....1....1 %K A254214 nonn %O A254214 1,1 %A A254214 _R. H. Hardin_, Jan 26 2015