%I A135757
%S A135757 1,2,20,924,184756,155117520,538257874440,7648690600760440,
%T A135757 442512540276836779204,103827421287553411369671120,
%U A135757 98527218530093856775578873054432
%N A135757 Central binomial coefficients at triangular positions: a(n) = A000984(n(n+1)/
               2).
%F A135757 a(n) = C(n(n+1), n(n+1)/2).
%o A135757 (PARI) a(n)=binomial(n*(n+1),n*(n+1)/2)
%Y A135757 Cf. A135758.
%Y A135757 Sequence in context: A163594 A013148 A006547 this_sequence A158843 A008793 
               A015192
%Y A135757 Adjacent sequences: A135754 A135755 A135756 this_sequence A135758 A135759 
               A135760
%K A135757 nonn
%O A135757 0,2
%A A135757 Paul D. Hanna (pauldhanna(AT)juno.com), Dec 02 2007