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 A255711 #6 Jul 23 2025 15:09:57 %S A255711 2,4,10,21,47,102,256,754,2169,5999,17237,49510,132956,339522,900236, %T A255711 2620855,8077245,24619352,71983144,205409149,584195761,1647027286, %U A255711 4572955010,12705583667,36182897964,106766407391,326242477740 %N A255711 Number of length n 1..(3+2) arrays with no leading partial sum equal to a prime and no consecutive values equal. %C A255711 Column 3 of A255716 %H A255711 R. H. Hardin, <a href="/A255711/b255711.txt">Table of n, a(n) for n = 1..210</a> %e A255711 Some solutions for n=4 %e A255711 ..4....4....1....1....1....1....1....1....4....4....4....4....4....1....1....1 %e A255711 ..2....5....3....5....5....3....3....5....2....2....5....5....5....5....3....3 %e A255711 ..4....1....4....4....3....4....2....4....3....4....1....3....3....3....5....5 %e A255711 ..2....2....1....2....5....2....4....5....1....5....4....2....4....1....1....3 %Y A255711 Cf. A255716 %K A255711 nonn %O A255711 1,1 %A A255711 _R. H. Hardin_, Mar 03 2015