Number of length n 1..(2+2) arrays with no leading partial sum equal to a prime.

Terms

a(0) =2a(1) =3a(2) =8a(3) =20a(4) =50a(5) =126a(6) =329a(7) =956a(8) =2897a(9) =8341a(10) =23238a(11) =66544a(12) =194686a(13) =555838a(14) =1532445a(15) =4225095a(16) =12140873a(17) =36623429a(18) =112964359a(19) =345148105a(20) =1027400959a(21) =2988415841a(22) =8604041257a(23) =24715209608a(24) =70743541258a(25) =201532200098a(26) =575286723544