A088752 Let CompositePi(n) = number of composite numbers <= n and PrimePi(n) = number of primes <= n, so that CompositePi(n) + PrimePi(n) = n. Then a(n) = floor(n*(n - PrimePi(n))/(n-1-PrimePi(n-1) + n - 2 - PrimePi(n-2))).

1, 4, 3, 4, 4, 5, 6, 6, 6, 7, 7, 8, 9, 9, 8, 9, 9, 10, 11, 12, 11, 12, 13, 14, 14, 15, 14, 15, 15, 16, 17, 18, 18, 19, 18, 19, 20, 21, 20, 21, 21, 22, 23, 24, 23, 24, 25, 26, 26, 27, 26, 27, 28, 29, 29, 30, 29, 30, 30, 31, 32, 33, 33, 34, 33, 34, 35, 36, 35, 36, 36, 37, 38, 39, 39

Offset

3,2

Links

Table of n, a(n) for n=3..77.

Mathematica

digits=200 a=Table[Floor[n*(n-PrimePi[n])/(n-1-PrimePi[n-1]+n-2-PrimePi[n-2])], {n, 3, digits}]

Crossrefs

Sequence in context: A056641 A010652 A332810 * A239594 A094948 A332472

Adjacent sequences: A088749 A088750 A088751 * A088753 A088754 A088755

Keyword

nonn

Author

Roger L. Bagula, Oct 14 2003

Status

approved