Fourth entry in row n of triangle in A169945.

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =29a(5) =52a(6) =96a(7) =160a(8) =277a(9) =450a(10) =712a(11) =1086a(12) =1657a(13) =2448a(14) =3636a(15) =5280a(16) =7635a(17) =10840a(18) =15392a(19) =21372a(20) =29655a(21) =40580a(22) =55282a(23) =74620a(24) =100651a(25) =134232a(26) =178922a(27) =236488a(28) =312019a(29) =408550