%I A083241
%S A083241 0,0,0,5,2,4,2,9,4,8,8,11,10,12,10,15,16,18,12,21,20
%N A083241 a(n)+a(n-1)+a(n-2)+a(n-3)=p[n], the n-th prime if p[n]>3, a(1)=a(2)=a(3)=0;
               .
%F A083241 A001221[a[n]-A000720[a[n]]]=1 and a[n]-A000720[a[n]] is in A025475.
%e A083241 a(3)+a(4)+a(5)+a(6)=5+2+4+2=p[6]=13
%t A083241 Do[s=Prime[n]-n; If[Equal[Length[FactorInteger[s]], 1]&&!PrimeQ[s], Print[Prime[n]]], 
               {n, 1, 100000}]
%Y A083241 Sequence in context: A073943 A019901 A157121 this_sequence A111145 A021660 
               A064853
%Y A083241 Adjacent sequences: A083238 A083239 A083240 this_sequence A083242 A083243 
               A083244
%K A083241 nonn
%O A083241 0,4
%A A083241 Labos E. (labos(AT)ana.sote.hu), Apr 24 2003