A176035 - OEIS

%I #2 Mar 31 2012 12:38:35

%S 2,1,5,6,5,6,1,8,9,10,2,3,10,2,6,8,9,13,1,5,10,13,1,4,5,6,10,12,13,14,

%T 6,11,15,18,19,1,2,8,12,13,20,21,22,1,2,11,14,15,17,22,8,9,14,16,18,

%U 25,5,6,7,9,10,13,17,18,19,21,22,23,25,1,10,12,22,24,28,29,3,6,9,11,18,22,31

%N Difference between product of two distinct primes and previous perfect square.

%C 6-4=2, 10-9=1, 14-9=5, 15-9=6, 21-16=5,..

%t f1[n_]:=Floor[Sqrt[n]];f2[n_]:=Last/@FactorInteger[n]=={1,1};lst={};Do[If[f2[n],AppendTo[lst,n-f1[n]^2]],{n,0,5!}];lst

%Y Cf. A006881, A056892, A106044, A176032, A176033, A176034

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Apr 06 2010