%I A084615
%S A084615 1,5,23,99,401,1525,6345,27331,122083,520805,2117293,8301441,34517395,
%T A084615 147850771,628707981,2675100397,10920387779,43701876543,180872758207,
%U A084615 769658883325,3243501133481,13617178197183,56148348498199
%N A084615 a(n) = sum of absolute values of coefficients of (1+x-3x^2)^n.
%o A084615 (PARI) for(n=0,40,S=0; for(k=0,2*n,t=polcoeff((1+x-3*x^2)^n,k,x); S=S+abs(t)); 
               print1(S","))
%Y A084615 Cf. A002426, A084600-A084614.
%Y A084615 Sequence in context: A055489 A109765 A119012 this_sequence A049674 A077277 
               A073682
%Y A084615 Adjacent sequences: A084612 A084613 A084614 this_sequence A084616 A084617 
               A084618
%K A084615 nonn
%O A084615 0,2
%A A084615 Paul D. Hanna (pauldhanna(AT)juno.com), Jun 01 2003