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 A254542 #6 Jul 23 2025 14:47:24 %S A254542 2,20,45,160,222,576,1026,1849,2461,4195,5217,8052,11098,15300,18210, %T A254542 25269,29296,38791,48468,60634,68591,87149,104149,126729,149195, %U A254542 177607,196492,236417,258581,301770,345756,398586,452724,522973,563863,640216 %N A254542 Number of length 4 1..(n+2) arrays with no leading partial sum equal to a prime. %C A254542 Row 4 of A254539 %H A254542 R. H. Hardin, <a href="/A254542/b254542.txt">Table of n, a(n) for n = 1..210</a> %e A254542 Some solutions for n=4 %e A254542 ..6....6....4....4....1....1....4....6....6....4....6....6....6....4....1....6 %e A254542 ..2....2....4....5....3....3....6....4....6....2....2....3....2....5....5....2 %e A254542 ..4....6....6....3....4....2....4....2....3....4....4....3....1....3....3....6 %e A254542 ..2....1....1....2....1....4....6....4....3....2....6....2....6....4....6....4 %K A254542 nonn %O A254542 1,1 %A A254542 _R. H. Hardin_, Feb 01 2015