Main diagonal of triangle A127496: a(n) = A127496(n,n) for n>=0.

Terms

a(0) =1a(1) =1a(2) =2a(3) =7a(4) =23a(5) =83a(6) =306a(7) =1135a(8) =4257a(9) =16095a(10) =61222a(11) =233956a(12) =897499a(13) =3454211a(14) =13331358a(15) =51575877a(16) =199954871a(17) =776642435a(18) =3021505570a(19) =11772342667a(20) =45927761857a(21) =179393034333a(22) =701465614758