The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #8 Nov 05 2025 15:22:48
%S -1,0,18,480,11550,275184,6597360,159629184,3897563670,95946708000,
%T 2378998624860,59359563244800,1489281975509328,37545821365718400,
%U 950601539891016000,24159023128878865920,616066120184552310150,15757649689979967739200
%N a(n) = -Sum_{k=0..n} (-1)^k * A039599(n,k)^3.
%H Pedro J. Miana, Hideyuki Ohtsuka, and Natalia Romero, <a href="https://arxiv.org/abs/1602.04347">Sums of powers of Catalan triangle numbers</a>, arXiv:1602.04347 [math.NT], 2016.
%F a(n) = ((n-1)/(2*n+1)) * binomial(2*n,n) * binomial(3*n,n).
%o (PARI) a(n) = (n-1)/(2*n+1)*binomial(2*n, n)*binomial(3*n, n);
%Y Cf. A039599.
%K sign
%O 0,3
%A _Seiichi Manyama_, Mar 24 2025