A336929 -id:A336929 - cp's OEIS frontend

A336928 a(n) = A329697(sigma(n)), where A329697 is totally additive with a(2) = 0 and a(p) = 1 + a(p-1) for odd primes.

0, 1, 0, 2, 1, 1, 0, 2, 2, 2, 1, 2, 2, 1, 1, 3, 2, 3, 1, 3, 0, 2, 1, 2, 3, 3, 1, 2, 2, 2, 0, 4, 1, 3, 1, 4, 3, 2, 2, 3, 3, 1, 2, 3, 3, 2, 1, 3, 4, 4, 2, 4, 3, 2, 2, 2, 1, 3, 2, 3, 3, 1, 2, 5, 3, 2, 1, 4, 1, 2, 2, 4, 3, 4, 3, 3, 1, 3, 1, 4, 4, 4, 3, 2, 3, 3, 2, 3, 3, 4, 2, 3, 0, 2, 2, 4, 4, 5, 3, 5, 2, 3, 2, 4, 1

Offset: 1

Antti Karttunen, Aug 11 2020

nonn

Antti Karttunen, Table of n, a(n) for n = 1..65537
Index entries for sequences related to sigma(n)

Cf. A000203, A329697.

Cf. also A336469, A336694, A336927, A336929.

A329697(n) = { my(f=factor(n)); sum(k=1,#f~,if(2==f[k,1],0,f[k,2]*(1+A329697(f[k,1]-1)))); };
A336928(n) = A329697(sigma(n));

Additive with a(p^e) = A329697(sigma(p^e)) = A329697(1+ p + p^2 + ... + p^e).

a(n) = A329697(A000203(n)).

A336927 Lexicographically earliest infinite sequence such that a(i) = a(j) => A335880(sigma(i)) = A335880(sigma(j)), for all i, j >= 1.

Original entry on oeis.org

1, 2, 1, 3, 2, 2, 1, 4, 5, 5, 2, 3, 3, 2, 2, 6, 5, 7, 8, 9, 1, 5, 2, 4, 6, 9, 8, 3, 4, 5, 1, 10, 2, 7, 2, 10, 7, 4, 3, 11, 9, 2, 5, 9, 7, 5, 2, 6, 12, 13, 5, 13, 7, 4, 5, 4, 8, 11, 4, 9, 6, 2, 5, 14, 9, 5, 15, 10, 2, 5, 5, 16, 11, 12, 6, 7, 2, 9, 8, 13, 12, 10, 9, 3, 7, 7, 4, 11, 11, 12, 3, 9, 1, 5, 4, 10, 13, 17, 7, 18, 19, 7, 5, 12, 2

Offset: 1

Antti Karttunen, Aug 11 2020

nonn

Restricted growth sequence transform of the function f(n) = A335880(A000203(n)), or equally, of the ordered pair [A336928(n), A336929(n)].

Antti Karttunen, Table of n, a(n) for n = 1..65537
Index entries for sequences related to sigma(n)

Cf. A000203, A335880, A336928, A336929.

Cf. also A336926.

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; };
A329697(n) = { my(f=factor(n)); sum(k=1,#f~,if(2==f[k,1],0,f[k,2]*(1+A329697(f[k,1]-1)))); };
A331410(n) = { my(f=factor(n)); sum(k=1,#f~,if(2==f[k,1],0,f[k,2]*(1+A331410(f[k,1]+1)))); };
Aux335880(n) = [A329697(n),A331410(n)];
v336927 = rgs_transform(vector(up_to, n, Aux335880(sigma(n))));
A336927(n) = v336927[n];

cp's OEIS Frontend

A336928 a(n) = A329697(sigma(n)), where A329697 is totally additive with a(2) = 0 and a(p) = 1 + a(p-1) for odd primes.

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