%I #4 Feb 01 2015 09:35:31
%S 2,3,8,20,50,126,329,956,2897,8341,23238,66544,194686,555838,1532445,
%T 4225095,12140873,36623429,112964359,345148105,1027400959,2988415841,
%U 8604041257,24715209608,70743541258,201532200098,575286723544
%N Number of length n 1..(2+2) arrays with no leading partial sum equal to a prime
%C Column 2 of A254539
%H R. H. Hardin, <a href="/A254533/b254533.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=4
%e ..4....1....4....4....4....4....4....4....1....1....1....1....4....4....4....1
%e ..2....3....4....4....2....4....4....2....3....3....3....3....2....2....4....3
%e ..3....4....1....4....2....4....2....4....4....2....2....4....2....2....1....2
%e ..3....1....3....3....2....2....4....4....4....4....3....2....4....1....1....2
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 01 2015