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A078859
Least positive residues (mod 210) representing those residue classes which can be the lesser of twin prime pairs (A001359).
9
3, 5, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 167, 179, 191, 197, 209
OFFSET
1,1
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.
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 *)
CROSSREFS
Sequence in context: A069233 A329946 A063700 * A054799 A093326 A001359
KEYWORD
fini,full,nonn
AUTHOR
Labos Elemer, Dec 13 2002
STATUS
approved