A073871 A073870 divided by n.

4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 2, 1, 1, 1, 2, 1, 2, 2, 1

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(1)=4, a(2) = a(3) = 3. For n > 3, if the odd part of n is 1, 9, or a prime, a(n) = 2, otherwise a(n) = 1. - Franklin T. Adams-Watters, May 12 2006

Prog

(PARI) A073871(n) = if(n<=3, 3+(1==n), my(op=n>>valuation(n, 2)); if(1==op || 9==op || isprime(op), 2, 1)); \\ Antti Karttunen, Jan 19 2025

Crossrefs

Cf. A073870.

Cf. A000265.

Sequence in context: A019975 A327869 A196274 * A120927 A241180 A117323

Adjacent sequences: A073868 A073869 A073870 * A073872 A073873 A073874

Keyword

nonn

Author

Amarnath Murthy, Aug 16 2002

Extensions

Corrected and extended by Franklin T. Adams-Watters, May 12 2006

Status

approved