function [a,b,c,est]=rkf45a
c = [0 2/9  1/3  3/4  1  5/6]';
a  = [zeros(1,6);2/9 zeros(1,5);1/12 1/4 zeros(1,4);69/128 -243/128 135/64 0 0 0;
     -17/12 27/4 -27/5 16/15 0 0;65/432 -5/16 13/16 4/27 5/144 0];
b = [47/450 0 12/25 32/225 1/30 6/25]';
est = [1/150 0 -3/100 16/75 1/20 -6/25]';