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A145992 Run lengths of 2 or more consecutive primes of the form 4k+3. 5
2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 7, 2, 2, 2, 2, 3, 2, 2, 5, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 5, 5, 2, 2, 4, 2, 2, 3, 2, 2, 3, 4, 2, 2, 3, 3, 2, 3, 2, 3, 2, 2, 2, 2, 2, 3, 3, 2, 3, 3, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 2, 2, 4, 2, 2, 3, 2, 3, 3, 2, 3, 4, 2, 2, 2, 4, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

Enoch Haga, Exploring Primes on Your PC and the Internet, 1994-2007. Pp. 30-31. ISBN 978-1-885794-24-6

LINKS

Table of n, a(n) for n=1..102.

EXAMPLE

a(1) = 2 counts the two 3's from A039702(4) to A039072(5).

a(9) = 4 counts the four 3's from A039702(46) to A039072(49).

a(14)= 7 counts the seven 4's from A039702(90) to A039072(96).

MAPLE

A145992 := proc()

    local m, p, r, i ;

    m := 3 ;

    p := 2 ;

    r := 0 ;

    for i from 2 to 1000 do

        if modp(p, 4) = m then

            r := r+1 ;

        else

            if r > 1 then

                printf("%d, ", r) ;

            end if;

            r := 0;

        end if;

        p := nextprime(p) ;

    end do:

end proc:

A145992() ; # R. J. Mathar, Aug 29 2018

MATHEMATICA

Most[Length /@ Select[ SplitBy[ Prime@ Range@ 780, Mod[#, 4] &], Mod[#[[1]], 4] == 3 && Length[#] > 1 &]] (* Giovanni Resta, Aug 29 2018 *)

CROSSREFS

Cf. A039702, A055623, A145986, A145988, A145989, A145990, A145991, A145993, A145994.

Sequence in context: A277090 A103376 A189819 * A045818 A064128 A248774

Adjacent sequences:  A145989 A145990 A145991 * A145993 A145994 A145995

KEYWORD

easy,nonn

AUTHOR

Enoch Haga, Oct 26 2008

EXTENSIONS

Corrected by R. J. Mathar, Aug 29 2018

STATUS

approved

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Last modified May 24 18:34 EDT 2019. Contains 323534 sequences. (Running on oeis4.)