A351561 a(n) = n + d(n) - phi(n), where d is the number of divisors function, and phi is the Euler totient function.
1, 3, 3, 5, 3, 8, 3, 8, 6, 10, 3, 14, 3, 12, 11, 13, 3, 18, 3, 18, 13, 16, 3, 24, 8, 18, 13, 22, 3, 30, 3, 22, 17, 22, 15, 33, 3, 24, 19, 32, 3, 38, 3, 30, 27, 28, 3, 42, 10, 36, 23, 34, 3, 44, 19, 40, 25, 34, 3, 56, 3, 36, 33, 39, 21, 54, 3, 42, 29, 54, 3, 60, 3, 42, 41, 46, 21, 62, 3, 58, 32, 46, 3, 72, 25, 48
Offset: 1
Keywords
Links
- Antti Karttunen, Table of n, a(n) for n = 1..20000
Crossrefs
Programs
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Mathematica
Array[# + DivisorSigma[0, #] - EulerPhi[#] &, 86] (* Michael De Vlieger, Feb 21 2022 *)
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PARI
A351561(n) = (n+numdiv(n)-eulerphi(n));