A080212 Binomial(n, smallest odd prime factor of n).

1, 2, 1, 4, 1, 20, 1, 8, 84, 252, 1, 220, 1, 3432, 455, 16, 1, 816, 1, 15504, 1330, 705432, 1, 2024, 53130, 10400600, 2925, 1184040, 1, 4060, 1, 32, 5456, 2333606220, 324632, 7140, 1, 35345263800, 9139, 658008, 1, 11480, 1, 7669339132, 14190

Offset

1,2

Comments

For n>1: a(n)=1 iff n is prime.

Links

Table of n, a(n) for n=1..45.

Crossrefs

Cf. A078701, A080211, A080213.

Sequence in context: A128271 A092891 A229484 * A186727 A145998 A218952

Adjacent sequences: A080209 A080210 A080211 * A080213 A080214 A080215

Keyword

nonn

Author

Reinhard Zumkeller, Feb 06 2003

Status

approved