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A071701
Number of twin prime pairs <= n of form (4*k+1,4*k+3), k>0.
1
0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 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, 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, 4, 4, 4, 4
OFFSET
1,17
COMMENTS
As for A071538 the convention is followed that a twin prime pair is <= n if its smaller member is <= n.
EXAMPLE
a(30)=3, since (29,31) is included along with (5,7) and (17,19).
CROSSREFS
a(n) = A071538(n) - A071702(n), cf. A071695, A071696.
Sequence in context: A179076 A095861 A111855 * A342696 A064459 A279758
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jun 04 2002
STATUS
approved