A080212 - OEIS

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A080212

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

%I #3 Mar 30 2012 18:50:31

%S 1,2,1,4,1,20,1,8,84,252,1,220,1,3432,455,16,1,816,1,15504,1330,

%T 705432,1,2024,53130,10400600,2925,1184040,1,4060,1,32,5456,

%U 2333606220,324632,7140,1,35345263800,9139,658008,1,11480,1,7669339132,14190

%N Binomial(n, smallest odd prime factor of n).

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

%Y Cf. A078701, A080211, A080213.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Feb 06 2003