A351035 Lexicographically earliest infinite sequence such that a(i) = a(j) => A347385(i) = A347385(j) and A336158(i) = A336158(j), for all i, j >= 1.

1, 1, 2, 1, 3, 2, 4, 1, 5, 3, 6, 2, 7, 4, 8, 1, 9, 5, 10, 3, 11, 6, 12, 2, 13, 7, 14, 4, 15, 8, 16, 1, 17, 9, 17, 5, 18, 10, 19, 3, 20, 11, 21, 6, 22, 12, 23, 2, 24, 13, 25, 7, 26, 14, 25, 4, 27, 15, 28, 8, 29, 16, 30, 1, 31, 17, 32, 9, 33, 17, 34, 5, 35, 18, 36, 10, 33, 19, 37, 3, 38, 20, 39, 11, 40, 21, 41, 6, 42

Offset: 1

Author

Antti Karttunen, Jan 30 2022

Keywords

• nonn
• easy

Comments

Restricted growth sequence transform of the ordered pair [A347385(n), A336158(n)], where A347385(n) is the Dedekind psi function applied to the odd part of n, i.e., A001615(A000265(n)), and A336158(n) is the least representative of the prime signature of the odd part of n.

For all i, j >= 1: A003602(i) = A003602(j) => a(i) = a(j).

Examples

			a(33) = a(35) as both 33 = 3*11 and 35 = 5*7 are odd nonsquare semiprimes, thus A336158 gives equal values for them, and also A347385(33) = A001615(33) = A347385(35) = A001615(35) = 48.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A000265, A001615, A003602, A046523, A336158, A351035.

Differs from A347374 for the first time at n=103, where a(103) = 48, while A347374(103) = 30.

Differs from A351036 for the first time at n=175, where a(175) = 78, while A351036(175) = 80.

Programs

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; };
A000265(n) = (n>>valuation(n,2));
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
A336158(n) = A046523(A000265(n));
A347385(n) = if(1==n,n, my(f=factor(n>>valuation(n, 2))); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1)));
Aux351035(n) = [A347385(n), A336158(n)];
v351035 = rgs_transform(vector(up_to, n, Aux351035(n)));
A351035(n) = v351035[n];