OFFSET
1,2
LINKS
PROG
(PARI)
up_to = 65537;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };
A006370(n) = if(n%2, 3*n+1, n/2);
A322973aux(n) = if(1==n, 0, if((n>2)&&isprime(n), -1, A006370(n)));
v322973 = rgs_transform(vector(up_to, n, A322973aux(n)));
A322973(n) = v322973[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 05 2019
STATUS
approved