OFFSET
0,3
COMMENTS
Restricted growth sequence transform of A324058.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..65537
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; };
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
A324121(n) = gcd(sigma(n), n*numdiv(n));
v336320 = rgs_transform(vector(1+up_to, n, A324058(n-1)));
A336320(n) = v336320[1+n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 19 2020
STATUS
approved