A048689 - OEIS

%I #13 Jul 07 2018 19:17:24

%S 1,2,2,2,3,3,3,3,3,5,5,5,5,5,5,5,5,5,5,7,7,8,7,7,7,8,8,8,8,9,8,9,9,10,

%T 9,10,11,10,10,11,9,10,11,11,12,12,12,12,10,12,11,12,13,11,13,14,13,

%U 12,12,13,13,14,11,14,13,14,14,12,13,16,15,14,14,15,14,16,13,17,15,14,16

%N Number of classes generated by function A001222 when applied to binomial coefficients.

%H G. C. Greubel, <a href="/A048689/b048689.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = length(union(A001222(binomial(n,k)))), for 0 <= k <= n.

%e For n=9, A001222({C(9,k)}) = {0,2,4,4,4,4,4,4,2,0} includes 3 distinct values, thus generating 3 classes of k values: {0,9},{1,8} and {2,3,4,5,6,7}. So a(9)=3.

%t Table[Length[Union[Table[PrimeOmega[Binomial[n, k]], {k, 0, n}]]], {n,

%t    1, 50}] (* _G. C. Greubel_, May 19 2017 *)

%Y Cf. A000005, A001221, A007947, A001222.

%K nonn

%O 1,2

%A _Labos Elemer_