a(n) = Sum_{k=0..n} A001595(k)^2.

Terms

a(0) =1a(1) =2a(2) =11a(3) =36a(4) =117a(5) =342a(6) =967a(7) =2648a(8) =7137a(9) =19018a(10) =50347a(11) =132716a(12) =348941a(13) =915950a(14) =2401911a(15) =6294640a(16) =16489889a(17) =43187778a(18) =113094099a(19) =296127940a(20) =775343821a(21) =2029991062a(22) =5314771031a(23) =13914551256a(24) =36429253657a(25) =95373809882a(26) =249693147107a(27) =653707202748