A symmetrical triangle read by rows: T(n, k) = 2^n*(q^k - 1)*(q^(n - k) - 1) + 1, where q = 2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =1a(6) =1a(7) =25a(8) =25a(9) =1a(10) =1a(11) =113a(12) =145a(13) =113a(14) =1a(15) =1a(16) =481a(17) =673a(18) =673a(19) =481a(20) =1a(21) =1a(22) =1985a(23) =2881a(24) =3137a(25) =2881a(26) =1985a(27) =1a(28) =1a(29) =8065