I wrote the following script to calculate terms of A060322. It does a decent job, but takes a lot of memory: at present I can only calculate around 70 terms. Can anyone suggest a way to push it further?
A060322(n)= /* Provide an array from 1..n of the number of integers with a stopping time of _n_ */
{
my(v=vector(n,i,[]));
v[1]=[1];
my(v2=v3=v4=[]);
if(n>4,
for(x=5,n,
v2=vector(x-1,i,[(x-1)/3| x<-2^(x-i)*v[i],(x%3)==1]);
v[x]=concat(v2);
)
);
v3=vector(#v,i,#v[i]);
v4=vector(#v,i,vecsum(v3[1..i]));
return(v4)
}
All the best,
Joe Slater