%I A047918
%S A047918 1,2,0,6,0,0,8,0,0,16,20,0,0,0,100,12,24,36,0,0,648,42,0,0,0,0,
%T A047918 0,4998,32,32,0,320,0,0,0,39936,54,0,270,0,0,0,0,0,362556,40,160,
%U A047918 0,0,3800,0,0,0,0,3624800,110,0,0,0,0,0,0,0,0,0,39916690,48,96
%N A047918 Triangular array a(n,k) = Sum_{d|k} mu(d)*U(n,k/d) if k|n else 0, where 
               U(n,k)=A047916(n,k) (1<=k<=n).
%D A047918 J. E. A. Steggall, On the numbers of patterns which can be derived from 
               certain elements, Mess. Math., 37 (1907), 56-61.
%Y A047918 Sequence in context: A137260 A153059 A151336 this_sequence A138701 A050821 
               A076257
%Y A047918 Adjacent sequences: A047915 A047916 A047917 this_sequence A047919 A047920 
               A047921
%K A047918 nonn,tabl,nice,easy
%O A047918 0,2
%A A047918 N. J. A. Sloane (njas(AT)research.att.com).