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 A254534 #6 Jul 23 2025 14:46:29 %S A254534 2,5,15,45,135,421,1466,5403,19417,69205,249569,883285,3024282, %T A254534 10359274,37010151,138333876,524680726,1964881580,7214899381, %U A254534 26104002605,93449335588,331875353107,1177784053061,4229817098432,15554800422055 %N A254534 Number of length n 1..(3+2) arrays with no leading partial sum equal to a prime. %C A254534 Column 3 of A254539 %H A254534 R. H. Hardin, <a href="/A254534/b254534.txt">Table of n, a(n) for n = 1..210</a> %e A254534 Some solutions for n=4 %e A254534 ..1....4....4....4....4....1....4....1....4....4....1....1....1....4....1....4 %e A254534 ..3....5....4....5....2....3....4....3....2....5....5....5....3....5....5....5 %e A254534 ..5....3....4....5....2....4....2....2....2....1....4....2....2....3....3....3 %e A254534 ..3....2....3....2....1....4....2....4....2....2....5....4....2....4....3....3 %K A254534 nonn %O A254534 1,1 %A A254534 _R. H. Hardin_, Feb 01 2015