A171626 a(n) = ceiling(n-th noncomposite/n).

1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6

Offset

1,4

Comments

Numerators and denominators of A008578(n)/n are A171525(n) and A171526(n).

Links

Andrew Howroyd, Table of n, a(n) for n = 1..10000

Formula

a(n) = ceiling(A008578(n)/n).

a(n) = A171622(n) + 1 for n >= 4.

Prog

(PARI) a(n) = if(n==1, 1, (prime(n-1)-1)\n+1); \\ Andrew Howroyd, Oct 29 2025

Crossrefs

Cf. A008578 (noncomposite), A171525, A171526, A171622

Sequence in context: A052375 A212625 A309398 * A074279 A072750 A235037

Adjacent sequences: A171623 A171624 A171625 * A171627 A171628 A171629

Keyword

nonn

Author

Jaroslav Krizek, Dec 13 2009

Extensions

Corrected by Jaroslav Krizek, Dec 16 2009

a(51) onward from Andrew Howroyd, Oct 29 2025

Status

approved