A071702 Number of twin prime pairs <= n of form (4*k+3,4*(k+1)+1), k>=0.
0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
Offset: 1
Keywords
Examples
a(60)=3, since (59,61) is included along with (3,5) and (11,13).
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Accumulate[Table[If[AllTrue[{n,n+2},PrimeQ]&&Mod[n,4]==3,1,0],{n,100}]] (* Harvey P. Dale, Nov 12 2021 *)
Comments