0,4
A001221[a[n]-A000720[a[n]]]=1 and a[n]-A000720[a[n]] is in A025475.
a(3)+a(4)+a(5)+a(6)=5+2+4+2=p[6]=13
Do[s=Prime[n]-n; If[Equal[Length[FactorInteger[s]], 1]&&!PrimeQ[s], Print[Prime[n]]], {n, 1, 100000}]
Adjacent sequences: A083238 A083239 A083240 this_sequence A083242 A083243 A083244
Sequence in context: A073943 A019901 A157121 this_sequence A111145 A021660 A064853
nonn
Labos E. (labos(AT)ana.sote.hu), Apr 24 2003
Search completed in 0.002 seconds