OFFSET
0,2
COMMENTS
Restricted growth sequence transform of A366875.
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));
A113415(n) = if(n<1, 0, sumdiv(n, d, if(d%2, (d+1)/2)));
memoA349915 = Map();
A349915(n) = if(1==n, 1, my(v); if(mapisdefined(memoA349915, n, &v), v, v = -sumdiv(n, d, if(d<n, A113415(n/d)*A349915(d), 0)); mapput(memoA349915, n, v); (v)));
v366878 = rgs_transform(vector(1+up_to, n, A366875(n-1)));
A366878(n) = v366878[1+n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 27 2023
STATUS
approved