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; };
A009194(n) = gcd(n, sigma(n));
Aux325384(n) = if((n%2)&&isprime(n), 0, [sigma(n), A009194(n)]);
v325384 = rgs_transform(vector(up_to, n, Aux325384(n)));
A325384(n) = v325384[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 08 2019
STATUS
approved