A067349 - OEIS

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A067349

Number of divisors of sigma(n)+phi(n).

2, 3, 4, 3, 4, 4, 4, 2, 2, 4, 4, 6, 4, 8, 6, 4, 4, 6, 4, 6, 6, 4, 4, 6, 4, 8, 4, 6, 4, 10, 4, 2, 6, 8, 12, 2, 4, 8, 10, 4, 4, 12, 4, 8, 8, 4, 4, 12, 6, 2, 8, 4, 4, 8, 10, 15, 6, 4, 4, 8, 4, 12, 12, 4, 12, 6, 4, 4, 12, 16, 4, 4, 4, 12, 6, 10, 12, 14, 4, 4, 6, 4, 4, 8, 6, 8, 10, 12, 4, 8, 8, 6, 6, 8

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A000005(A000010(n) + A000203(n)).

MATHEMATICA

Table[ DivisorSigma[ 0, DivisorSigma[ 1, w ]+EulerPhi[ w ] ], {w, 1, 128} ]

PROG

(PARI) a(n) = numdiv(sigma(n)+eulerphi(n)); \\ Michel Marcus, Aug 13 2019

CROSSREFS