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 A254217 #7 Jan 27 2015 18:01:57 %S A254217 5,12,48,168,766,3720,18214,81428,362910,1828848,9781293,49824190, %T A254217 241134125,1198202218,6489872942,36558663886,196996500006, %U A254217 982525116524,4694315336320,23819615009274,140719786602875,913403203820358,5715151962243604,32271875770787666 %N A254217 Number of length n 1..(7+2) arrays with no leading or trailing partial sum equal to a prime and no consecutive values equal. %e A254217 Some solutions for n=4: %e A254217 ..6....4....4....6....4....8....4....4....1....4....1....8....1....4....9....6 %e A254217 ..8....8....6....9....6....2....2....8....3....2....8....1....5....8....3....4 %e A254217 ..2....2....2....3....5....5....3....3....5....3....5....6....6....4....4....5 %e A254217 ..4....6....8....9....9....1....1....9....1....9....1....9....4....8....8....1 %Y A254217 Column k=7 of A254218. %K A254217 nonn %O A254217 1,1 %A A254217 _R. H. Hardin_, Jan 26 2015 %E A254217 a(19)-a(24) from _Alois P. Heinz_, Jan 27 2015