Search: id:A038142 Results 1-1 of 1 results found. %I A038142 %S A038142 1,1,2,5,12,36,118,411,1489,5572,21115 %N A038142 Number of planar cata-polyhexes with n cells. %C A038142 Number of cata-condensed benzenoid hydrocarbons with n hexagons. %C A038142 a(n) is the number of n-celled polyhexes with perimeter 4n+2. 4n+2 is the maximal perimeter of an n-celled polyhex. a(n) is the number of n-celled polyhexes that have a tree as their connectedness graph (vertices of this graph correspond to cells and two vertices are connected if the corresponding cells have a common edge) - Tanya Khovanova (tanyakh(AT)yahoo.com), Jul 27 2007 %D A038142 J. V. Knop et al., On the total number of polyhexes, Match, No. 16 (1984), 119-134. %D A038142 N. Trinajstich, Z. Jerievi, J. V. Knop, W. R. Muller and K. Szymanski, COMPUTER GENERATION OF ISOMERIC STRUCTURES, Pure & Appl. Chem., Vol. 55, No. 2, pp. 379-39O, 1983. %H A038142 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %H A038142 Isoperimetrical Polyhexes %H A038142 Poly Pages %H A038142 Eric Weisstein's World of Mathematics, Fusene %Y A038142 Cf. A018190, A038143. %Y A038142 a(n) <= A000228(n), a(n) <= A057779(2n+1). %Y A038142 Sequence in context: A108555 A032203 A094717 this_sequence A052302 A009598 A002216 %Y A038142 Adjacent sequences: A038139 A038140 A038141 this_sequence A038143 A038144 A038145 %K A038142 nonn %O A038142 1,3 %A A038142 N. J. A. Sloane (njas(AT)research.att.com). %E A038142 a(11) from Tanya Khovanova (tanyakh(AT)yahoo.com), Jul 27 2007 Search completed in 0.001 seconds