login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A275022 Primes not in A001097 and not in A275021 that occur in pairs of the form {p, p+6}. 0
47, 53, 251, 257, 331, 337, 353, 359, 367, 373, 541, 547, 557, 563, 587, 593, 607, 613, 647, 653, 727, 733, 947, 953, 977, 983, 991, 997, 1097, 1103, 1117, 1123, 1181, 1187, 1361, 1367, 1433, 1439, 1493, 1499, 1657, 1663, 1741, 1747, 1753 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

List of prime numbers that occur in pairs of the form {p, p+6} after the sequential removal, from a list of all the primes, of (1) the one pair of primes of the form {p, p+1}, (2) all remaining twin prime pairs {p, p+2}, and (3) all remaining pairs of the form {p, p+4}.

Conjecture: The sequence has infinitely many terms and the sum of their reciprocals converges.

LINKS

Table of n, a(n) for n=1..45.

PROG

(PARI) {

/* For biggest n allocatemem(max)*/

n=10^4-1;

v=vector(n, unused, 1);

for(i=2, sqrt(n),

    if(v[i],

       forstep(j=i^2, n, i, v[j]=0))

      );

v[2]=0; v[3]=0;

for(i=5, n-2,

     if(v[i]&&v[i+2],

        v[i]=0; v[i+2]=0

       )

    );

for(i=5, n-4,

     if(v[i]&&v[i+4],

        v[i]=0; v[i+4]=0;

       )

    );

for(i=5, n-6,

     if(v[i]&&v[i+6],

        print1(i", "i+6", ");

        v[i]=0; v[i+6]=0;

       )

    )

}

CROSSREFS

Cf. A001097, A275021.

Sequence in context: A141279 A155139 A106279 * A048581 A169716 A045140

Adjacent sequences:  A275019 A275020 A275021 * A275023 A275024 A275025

KEYWORD

nonn,more

AUTHOR

Dimitris Valianatos, Nov 12 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 28 22:52 EST 2020. Contains 332336 sequences. (Running on oeis4.)