OFFSET
0,4
COMMENTS
Restricted growth sequence transform of A366887.
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; };
A163511(n) = if(!n, 1, my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
A206787(n) = sumdiv(n, d, d*issquarefree(2*d));
v366888 = rgs_transform(vector(1+up_to, n, A366887(n-1)));
A366888(n) = v366888[1+n];
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Nov 04 2023
STATUS
approved