A089282 Number of distinct prime factors of floor(Pi*10^n), Pi=3.14...

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

Offset

0,3

Links

Table of n, a(n) for n=0..80.

Formula

a(n) = A001221(A011545(n)).

Example

n=6: floor(Pi*10^6) = 3141592 = 2*2*2*392699: a(6)=2.

Mathematica

Table[PrimeNu[Floor[Pi 10^n]], {n, 0, 80}] (* Harvey P. Dale, Dec 19 2022 *)

Crossrefs

Cf. A001221, A011545, A089283, A000796.

Sequence in context: A055460 A067514 A115323 * A308640 A369852 A079688

Adjacent sequences: A089279 A089280 A089281 * A089283 A089284 A089285

Keyword

nonn

Author

Reinhard Zumkeller, Oct 30 2003

Extensions

More terms from Ray Chandler, Oct 31 2003

Status

approved