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

9

`%I #10 May 15 2017 23:05:43
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`%S 3,5,11,17,29,41,59,71,101,107,137,149,167,179,191,197,209
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`%N Least positive residues (mod 210) representing those residue classes which can be the lesser of twin prime pairs (A001359).
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`%F 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.
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`%t 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 *)
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`%Y Cf. A001359, A008364.
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`%K fini,full,nonn
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`%O 1,1
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`%A _Labos Elemer_, Dec 13 2002
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