A088347 - OEIS

%I #17 Jul 05 2021 10:53:11

%S 2,1,1,5,1,1,1,9,1,1,12,1,1,15,1,1,1,19,1,1,22,1,1,1,26,1,1,29,1,1,32,

%T 1,1,1,36,1,1,39,1,1,1,43,1,1,46,1,1,1,50,1,1,53,1,1,56,1,1,1,60,1,1,

%U 63,1,1,1,67,1,1,70,1,1,73,1,1,1,77,1,1,80,1,1,1,84,1,1,87,1,1,90,1,1,1,94,1

%N This sequence needs a definition.

%C Subsequence of terms != 1 appears to give A063957. - _Joerg Arndt_, Jul 05 2021

%t (* generate the semiprimes *)

%t digits=20

%t a=Flatten[Table[Prime[i]*Prime[j], {i, 1, digits}, {j, 1, digits}]];

%t b=Union[a]

%t f[n_]=b[[n]]

%t (* factorial cancellation function *)

%t p[n_]=n!/Product[f[i], {i, 1, Floor[Sqrt[n^2/2+n/2]]}]

%t (* pick out the numbers *)

%t a1=Table[If[Floor[p[n+1]/p[n]]<n, 1, Floor[p[n+1]/p[n]]], {n, 1, 209}]

%K nonn,uned,less

%O 0,1

%A _Roger L. Bagula_, Nov 07 2003