%I #18 Aug 04 2017 04:14:13
%S 1,1,3,6,15,42,131,442,1551,5723,22171,89156,370199,1589240,7020127,
%T 31906974
%N Number of hypermaps which are self-equivalent with respect to reversing the colors of the nodes and which have n edges.
%H M. Deryagina, <a href="ftp://ftp.pdmi.ras.ru/pub/publicat/znsl/v446/p031.pdf">On the enumeration of hypermaps which are self-equivalent with respect to reversing the colors of vertices</a>, Preprint 2016.
%F a(n) = 2*A234278(n) - 2*A057005(n).
%Y Cf. A057005, A234278.
%K nonn,more
%O 1,3
%A _N. J. A. Sloane_, Aug 03 2017