a(n) = [ n/{n*sqrt(2)} ], where {x} := x - [ x ].

Terms

a(0) =2a(1) =2a(2) =12a(3) =6a(4) =70a(5) =12a(6) =7a(7) =25a(8) =12a(9) =70a(10) =19a(11) =12a(12) =33a(13) =17a(14) =70a(15) =25a(16) =408a(17) =39a(18) =21a(19) =70a(20) =30a(21) =195a(22) =43a(23) =25a(24) =70a(25) =33a(26) =146a(27) =46a(28) =2378a(29) =70