OFFSET
1,2
COMMENTS
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
PROG
(PARI)
up_to = 8192;
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; };
A289271(n) = { my(v=0, i=0, x=1); for(d=2, oo, if(n==1, return(v)); if(1==gcd(x, d)&&1==omega(d), if(!(n%d)&&1==gcd(d, n/d), v += 2^i; n /= d; x *= d); i++)); }; \\ After Rémy Sigrist's program for A289271.
A289272(n) = { my(m=1, pp=1); while(n>0, pp++; while(!isprimepower(pp)||(gcd(pp, m)>1), pp++); if(n%2, m *= pp); n >>=1); (m); }; \\ Antti Karttunen, Jan 02 2019
A322988aux(n) = if(2==n, -1, if(isprimepower(n), 0, A322990(n)));
v322988 = rgs_transform(vector(up_to, n, A322988aux(n)));
A322988(n) = v322988[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 02 2019
STATUS
approved