OFFSET
1,2
COMMENTS
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
EXAMPLE
a(429) = a(455) because 429 = 3*11*13 and 455 = 5*7*13, so they have equal largest prime factor (A006530), and they also agree on A206787(429) = A206787(455) = 672 and on A336651(429) = A336651(455) = 1 (because both are squarefree), therefore they get equal value (which is 216) allotted to them by the restricted growth sequence transform. - Antti Karttunen, Feb 14 2022
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; };
A006530(n) = if(1==n, n, my(f=factor(n)); f[#f~, 1]);
A336651(n) = { my(f=factor(n)); prod(i=1, #f~, if(2==f[i, 1], 1, f[i, 1]^(f[i, 2]-1))); };
v351460 = rgs_transform(vector(up_to, n, Aux351460(n)));
A351460(n) = v351460[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 11 2022
STATUS
approved