A336848 a(n) = A003973(n) / A336846(n).

1, 2, 3, 13, 4, 2, 6, 10, 31, 8, 7, 13, 9, 4, 12, 121, 10, 62, 12, 52, 18, 14, 15, 2, 19, 6, 39, 26, 16, 8, 19, 182, 21, 20, 24, 403, 21, 8, 27, 40, 22, 12, 24, 7, 124, 10, 27, 121, 133, 38, 6, 13, 30, 26, 4, 20, 36, 32, 31, 52, 34, 38, 62, 1093, 36, 14, 36, 130, 9, 16, 37, 62, 40, 14, 57, 52, 42, 18, 42, 484, 781

Offset: 1

Author

Antti Karttunen, Aug 06 2020

Keywords

• nonn

Comments

If there are no more 1's in this sequence after the initial one, then there are no odd terms of A001599 (Ore's Harmonic Numbers) larger than one.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16383
• Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537
• Index entries for sequences computed from indices in prime factorization
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000005, A000203, A001599, A003961, A003973, A336845, A336846, A336847, A336849.

Programs

PARI

A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A336848(n) = { my(u=A003961(n),s=sigma(u)); (s/gcd(s, numdiv(n)*u)); };

Formula

a(n) = A003973(n) / A336846(n).