A061716 Binary order of n-th prime.

1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10

Offset

1,2

Comments

Apart from the first terms, the same as A035100. - R. J. Mathar, Oct 02 2008

Links

Harry J. Smith, Table of n, a(n) for n = 1..2000

Formula

a(n) = ceiling(log_2(prime(n))) = A029837(A000040(n)).

Mathematica

Ceiling[Log2[Prime[Range[110]]]] (* Harvey P. Dale, Apr 12 2023 *)

Prog

(PARI) { default(realprecision, 100); n=0; t=1/log(2); forprime (p=2, prime(2000), write("b061716.txt", n++, " ", ceil(t*log(p))) ) } \\ Harry J. Smith, Jul 26 2009

Crossrefs

Cf. A029837, A000040, A003070, A045716, A045716, A036378.

Sequence in context: A130500 A072073 A320757 * A362692 A341053 A126236

Adjacent sequences: A061713 A061714 A061715 * A061717 A061718 A061719

Keyword

nonn

Author

Labos Elemer, Jun 20 2001

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Jul 26 2009

Status

approved