%I A084604
%S A084604 1,1,1,4,1,2,9,8,16,1,3,15,25,60,48,64,1,4,22,52,145,208,352,256,256,1,
%T A084604 5,30,90,285,561,1140,1440,1920,1280,1024,1,6,39,140,495,1206,2841,4824,
%U A084604 7920,8960,9984,6144,4096,1,7,49,203,791,2261,6027,12489,24108,36176
%N A084604 Triangle, read by rows, where the n-th row lists the (2n+1) coefficients 
               of (1+x+4x^2)^n.
%e A084604 Rows:
%e A084604 {1},
%e A084604 {1,1,4},
%e A084604 {1,2,9,8,16},
%e A084604 {1,3,15,25,60,48,64},
%e A084604 {1,4,22,52,145,208,352,256,256},
%e A084604 {1,5,30,90,285,561,1140,1440,1920,1280,1024},
%e A084604 {1,6,39,140,495,1206,2841,4824,7920,8960,9984,6144,4096},
%o A084604 (PARI) for(n=0,10, for(k=0,2*n,t=polcoeff((1+x+4*x^2)^n,k,x); print1(t",
               ")); print(" "))
%Y A084604 Cf. A002426, A084600-A084603, A084605-A084615.
%Y A084604 Sequence in context: A004160 A128077 A128078 this_sequence A152253 A024569 
               A159756
%Y A084604 Adjacent sequences: A084601 A084602 A084603 this_sequence A084605 A084606 
               A084607
%K A084604 nonn,tabl
%O A084604 0,4
%A A084604 Paul D. Hanna (pauldhanna(AT)juno.com), Jun 01 2003