Self-convolution of Sum(binomial(2*n, i), i=0..n).

Terms

a(0) =1a(1) =6a(2) =31a(3) =150a(4) =699a(5) =3178a(6) =14198a(7) =62604a(8) =273235a(9) =1182786a(10) =5085666a(11) =21743956a(12) =92522206a(13) =392066340a(14) =1655432524a(15) =6967724312a(16) =29245179267a(17) =122442487474a(18) =511487386730