%I #9 Dec 19 2015 13:17:08
%S 2,3,19,173,3976733
%N a(n) = least k such that A047988(k) = n.
%C Values calculated by Thomas Kantke (bytes.more(AT)ibm.net).
%K nonn,more
%O 0,1
%A _Christian G. Bower_, May 15 1999
%E Definition corrected by _R. J. Mathar_, Jun 26 2007