%I #12 Mar 17 2024 05:42:57
%S 1,6,217,13997,1283817,151778430,21902350480,3726598826676,
%T 729894290301789,161683308639785288,39960246577221138239,
%U 10900687898284398341055,3253179971490906621196740,1054372896576358319473872858,368810384314446516250937494104
%N a(n) = A258220(2n,n).
%H Vaclav Kotesovec, <a href="/A292692/b292692.txt">Table of n, a(n) for n = 0..290</a> (terms 0..200 from Alois P. Heinz)
%F a(n) ~ c * d^n * n! / sqrt(n), where d = 25.81959672662517201... and c = 0.28310309251343879... - _Vaclav Kotesovec_, Dec 01 2017
%F Conjecture: d = (51*sqrt(17) - 107)/4. - _Vaclav Kotesovec_, Mar 17 2024
%Y Cf. A258220.
%K nonn
%O 0,2
%A _Alois P. Heinz_, Sep 20 2017