Third terms of triple Peano sequence A071988.

Terms

a(0) =2a(1) =4a(2) =15a(3) =42a(4) =176a(5) =299a(6) =697a(7) =988a(8) =1794a(9) =3683a(10) =4526a(11) =7807a(12) =10701a(13) =12384a(14) =16262a(15) =23479a(16) =32568a(17) =36051a(18) =47972a(19) =57226a(20) =62269a(21) =79158a(22) =91964a(23) =113653a(24) =147537a(25) =166751a(26) =176954a(27) =198592a(28) =210043a(29) =234249