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A070193 Numbers n such that gcd(3n,8^n+1) = 3 but n does not divide the numerator of B(2n) (the Bernoulli numbers). 4
253, 1081, 1771, 2485, 2783, 3289, 4301, 4807, 5405, 5819, 7337, 7567, 7843, 9361, 10373, 10879, 11891, 12397, 12425, 13409, 13861, 14053, 14927, 15433, 17395, 17963, 18145, 18377, 18469, 19481, 19987, 20539, 20999, 22517, 23023, 24541 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Equivalently, n is in A070191 but not in A069040.
LINKS
MATHEMATICA
testb[n_] := Select[First/@FactorInteger[n], Mod[2n, #-1]==0&]=={}; test8[n_] := GCD[3n, PowerMod[8, n, 3n]+1]==3; Select[Range[25000], test8[ # ]&&!testb[ # ]&]
CROSSREFS
Sequence in context: A157356 A203085 A245790 * A054737 A123013 A183449
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)