Same rule as Aitken triangle (A011971) except a(0,0)=0, a(1,0)=1.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =3a(7) =4a(8) =6a(9) =9a(10) =9a(11) =12a(12) =16a(13) =22a(14) =31a(15) =31a(16) =40a(17) =52a(18) =68a(19) =90a(20) =121a(21) =121a(22) =152a(23) =192a(24) =244a(25) =312a(26) =402a(27) =523a(28) =523a(29) =644