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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,17

COMMENTS

As for A071538 the convention is followed that a twin prime pair is <= n if its smaller member is <= n.

LINKS

Table of n, a(n) for n=1..96.

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 * A064459 A279758 A082996

Adjacent sequences:  A071698 A071699 A071700 * A071702 A071703 A071704

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 04 2002

STATUS

approved

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Last modified February 25 14:07 EST 2021. Contains 341609 sequences. (Running on oeis4.)