A273723 - OEIS

%I #7 Jun 03 2016 06:44:37

%S 1,1,6,7484400,35417271278873496315860673177600000000

%N Number of ternary heaps on n levels (i.e., of (3^n-1)/2 elements).

%H Alois P. Heinz, <a href="/A273723/b273723.txt">Table of n, a(n) for n = 0..6</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/D-ary_heap">D-ary heap</a>

%F a(n) = A178008(A003462(n)).

%Y Column k=3 of A273712.

%Y Cf. A003462, A178008.

%K nonn

%O 0,3

%A _Alois P. Heinz_, May 28 2016