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 A254540 #6 Jul 23 2025 14:47:10 %S A254540 1,3,5,10,11,20,28,37,41,54,58,75,91,109,116,139,146,172,196,221,230, %T A254540 262,290,324,355,390,404,445,458,499,539,583,626,674,690,739,787,839, %U A254540 859,917,937,996,1052,1113,1136,1205,1267,1337,1402,1470,1496,1572,1639,1716 %N A254540 Number of length 2 1..(n+2) arrays with no leading partial sum equal to a prime. %C A254540 Row 2 of A254539 %H A254540 R. H. Hardin, <a href="/A254540/b254540.txt">Table of n, a(n) for n = 1..210</a> %e A254540 All solutions for n=4 %e A254540 ..4....1....6....4....1....6....6....6....4....4 %e A254540 ..6....3....6....5....5....2....3....4....2....4 %K A254540 nonn %O A254540 1,2 %A A254540 _R. H. Hardin_, Feb 01 2015