%I A018212
%S A018212 1,5,25,85,255,651,1519,3235,6470,12190,21942,37854,63090,101850,
%T A018212 160050,245322,367983,541035,781495,1110395,1554553,2146573,2927145,
%U A018212 3945045,5260060,6942988,9079292,11769100,15131700,19305540
%N A018212 Alkane (or paraffin) numbers l(11,n).
%D A018212 S. M. Losanitsch, Die Isomerie-Arten bei den Homologen der Paraffin-Reihe, 
               Chem. Ber. 30 (1897), 1917-1926.
%D A018212 Winston C. Yang (paper in preparation).
%H A018212 N. J. A. Sloane, <a href="classic.html#LOSS">Classic Sequences</a>
%F A018212 G.f.: (1+6*x^2+x^4)/((1-x)^5*(1-x^2)^4) [ N. J. A. Sloane (njas(AT)research.att.com) 
               ]
%F A018212 l(c, r) = 1/2 binomial(c+r-3, r) + 1/2 d(c, r), where d(c, r) is binomial((c 
               + r - 3)/2, r/2) if c is odd and r is even, 0 if c is even and r 
               is odd, binomial((c + r - 4)/2, r/2) if c is even and r is even, 
               binomial((c + r - 4)/2, (r - 1)/2) if c is odd and r is odd.
%Y A018212 Sequence in context: A147122 A051229 A058919 this_sequence A147274 A147034 
               A146460
%Y A018212 Adjacent sequences: A018209 A018210 A018211 this_sequence A018213 A018214 
               A018215
%K A018212 nonn
%O A018212 0,2
%A A018212 N. J. A. Sloane (njas(AT)research.att.com), Winston C. Yang (yang(AT)math.wisc.edu)