A053619 a(n) = round(n/(log(n)-1) - pi(n)).

-1, -8, 28, 8, 5, 5, 3, 3, 4, 4, 3, 3, 2, 3, 3, 3, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 3, 3, 2, 2, 1

Offset: 1

Author

Henry Bottomley, Mar 21 2000

Keywords

• sign

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000
• C. K. Caldwell, How Many Primes Are There?

Crossrefs

Cf. A000720, A052434, A052435.

Programs

Magma

[Round(n/(Log(n)-1) - #PrimesUpTo(n)): n in [1..110]]; // G. C. Greubel, May 16 2019

Mathematica

Table[Round[n/(Log[n] -1) -PrimePi[n]], {n, 1, 110}] (* G. C. Greubel, May 16 2019 *)

PARI

{a(n) = round(n/(log(n)-1) - primepi(n))}; \\ G. C. Greubel, May 16 2019

Sage

[round(n/(log(n)-1) - prime_pi(n)) for n in (1..110)] # G. C. Greubel, May 16 2019

Extensions

More terms from James Sellers, Mar 23 2000