%I A082397
%S A082397 1,2,5,11,26,62,153,385,988,2573,6786,18084,48621,131718,359193,985185,
%T A082397 2715972,7521567,20915256,58373586,163462815,459136809,1293223230,
%U A082397 3651864606,10336625731,29321683082,83344398533,237344961291
%N A082397 Number of directed aggregates of height <= 2 with n cells.
%D A082397 Fouad Ibn-Majdoub-Hassani. Combinatoire de polyominos et des tableaux 
               decales oscillants . These de Doctorat. Laboratoire de Recherche 
               en Informatique, Universite Paris-Sud XI, France.
%F A082397 a(n) = Sum_{k=1..n}(-1)^(k+1)*binomial(n+1, k+1)*binomial(k, floor((k-1)/
               2)). E.g.f.: -exp(x)*int(-BesselI(1, 2*x)+BesselI(2, 2*x), x)-exp(x)*(-BesselI(1, 
               2*x)+BesselI(2, 2*x)). - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 
               18 2003
%Y A082397 Sequence in context: A006138 A124217 A095981 this_sequence A051286 A025245 
               A079223
%Y A082397 Adjacent sequences: A082394 A082395 A082396 this_sequence A082398 A082399 
               A082400
%K A082397 nonn
%O A082397 1,2
%A A082397 Fouad IBN MAJDOUB HASSANI (fouad.ibnmajdoubhassani(AT)wanadoo.fr), Apr 
               14 2003
%E A082397 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 18 2003