A078859 Least positive residues (mod 210) representing those residue classes which can be the lesser of twin prime pairs (A001359).

3, 5, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 167, 179, 191, 197, 209

Offset: 1

Author

Labos Elemer, Dec 13 2002

Keywords

• fini
• full
• nonn

Crossrefs

Cf. A001359, A008364.

Programs

Mathematica

With[{n = 4}, Function[P, Join[Select[Prime@ Range@ n, NextPrime@ # == # + 2 &], Select[Partition[Select[Range[P + 1], CoprimeQ[#, P] &], 2, 1], Differences@ # == {2} &][[All, 1]]]]@ Product[Prime@ i, {i, n}]] (* Michael De Vlieger, May 15 2017 *)

Formula

Intersection[RRS(210), 2+RRS{210)]-2 and {3, 5}. RRS(210)=reduced residue system of 210=first 48=phi(210) terms of A008364; two additional term 3 and 5 are singular cases; 210k+r generates complete A001359 with suitable k and r taken from these 15+2 numbers.