Square array: T(n,k) = ((3^(n+1) + 1)^(k-1) + 2)/3, read by descending antidiagonals.

Terms

a(0) =1a(1) =4a(2) =1a(3) =34a(4) =10a(5) =1a(6) =334a(7) =262a(8) =28a(9) =1a(10) =3334a(11) =7318a(12) =2242a(13) =82a(14) =1a(15) =33334a(16) =204886a(17) =183790a(18) =19846a(19) =244a(20) =1a(21) =333334a(22) =5736790a(23) =15070726a(24) =4842262a(25) =177634a(26) =730a(27) =1a(28) =3333334a(29) =160630102