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

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(n) = A000005(n) + A051953(n) = n - A063070(n) = n + A000005(n) - A000010(n).

Mathematica

Array[# + DivisorSigma[0, #] - EulerPhi[#] &, 86] (* Michael De Vlieger, Feb 21 2022 *)

Prog

(PARI) A351561(n) = (n+numdiv(n)-eulerphi(n));

Crossrefs

Cf. A000005, A000010, A020488 (fixed points), A051953, A063070.

Cf. also A055517.

Sequence in context: A320045 A334481 A361679 * A029620 A204100 A048691

Adjacent sequences: A351558 A351559 A351560 * A351562 A351563 A351564

Keyword

nonn

Author

Antti Karttunen, Feb 21 2022

Status

approved