Partial sums of A014531.

Terms

a(0) =1a(1) =4a(2) =14a(3) =44a(4) =134a(5) =400a(6) =1184a(7) =3488a(8) =10253a(9) =30108a(10) =88386a(11) =259492a(12) =762085a(13) =2239120a(14) =6582280a(15) =19360432a(16) =56976859a(17) =167774428a(18) =494301778a(19) =1457104948a(20) =4297477252a(21) =12680944960a(22) =37436553544a(23) =110569987344a(24) =326713395019a(25) =965775778420