A082514 a(n) = pi(n) + tau(n).

1, 3, 4, 5, 5, 7, 6, 8, 7, 8, 7, 11, 8, 10, 10, 11, 9, 13, 10, 14, 12, 12, 11, 17, 12, 13, 13, 15, 12, 18, 13, 17, 15, 15, 15, 20, 14, 16, 16, 20, 15, 21, 16, 20, 20, 18, 17, 25, 18, 21, 19, 21, 18, 24, 20, 24, 20, 20, 19, 29, 20, 22, 24, 25, 22, 26, 21, 25, 23, 27, 22, 32, 23, 25

Offset: 1

Author

Labos Elemer, Apr 29 2003

Keywords

• easy
• nonn
• less

Crossrefs

Cf. A000010, A000005, A000720, A073757, A037228, A063070, A045763.

Programs

Mathematica

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

PARI

a(n) = primepi(n) + numdiv(n); \\ Michel Marcus, Dec 01 2021

Formula

a(n) = A000720(n) + A000005(n).

Extensions

Name changed by Wesley Ivan Hurt, Nov 30 2021