Diagonal sums of number triangle A188474.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =12a(5) =27a(6) =65a(7) =150a(8) =353a(9) =843a(10) =2014a(11) =4843a(12) =11713a(13) =28433a(14) =69292a(15) =169470a(16) =415754a(17) =1022868a(18) =2523120a(19) =6238645a(20) =15459561a(21) =38387191a(22) =95497612a(23) =237989801a(24) =594062697a(25) =1485141397a(26) =3718116380a(27) =9320941698a(28) =23396109986a(29) =58795356627