A336847 a(n) = A003973(n) - A336846(n).

0, 2, 4, 12, 6, 12, 10, 36, 30, 28, 12, 72, 16, 36, 44, 120, 18, 122, 22, 102, 68, 52, 28, 120, 54, 60, 152, 150, 30, 168, 36, 362, 80, 76, 92, 402, 40, 84, 104, 312, 42, 264, 46, 156, 246, 108, 52, 720, 132, 222, 100, 216, 58, 600, 84, 456, 140, 124, 60, 612, 66, 148, 366, 1092, 140, 312, 70, 258, 160, 360, 72

Offset: 1

Author

Antti Karttunen, Aug 06 2020

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Index entries for sequences computed from indices in prime factorization
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000005, A000203, A003961, A003973, A336845, A336846, A336848.

Programs

PARI

A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A336847(n) = { my(u=A003961(n),s=sigma(u)); (s-gcd(s, numdiv(n)*u)); };

Formula

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