a(n) = (1/7)*A290913(n).

Terms

a(0) =0a(1) =1a(2) =4a(3) =17a(4) =76a(5) =336a(6) =1484a(7) =6559a(8) =28988a(9) =128111a(10) =566184a(11) =2502240a(12) =11058600a(13) =48873265a(14) =215994436a(15) =954583169a(16) =4218761572a(17) =18644733936a(18) =82400035556a(19) =364165339279