OFFSET
1,1
COMMENTS
In this condition, we can draw the following graphic whose sides are primes.
c
*------*
| |
d| |b
e | *---*
*------------* | a
| |
| |
| |
f| |h
| |
| g |
*---------------*
Dickson's conjecture implies that there are infinitely many prime octuplets of forms such as x, x+4, x+10, x+12, x+18, x+22, x+28, x+30, and thus infinitely many members of the sequence. - Robert Israel, Sep 20 2017
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
Números y algo mas's blog, 1315 - Golígonos, Goliedros y demás.
EXAMPLE
If a = 359, b, c, d, e, f, g, h = 367, 373, 379, 383, 389, 397, 401.
MAPLE
Primes:= select(isprime, [2, seq(i, i=3..10^5, 2)]):
Primes[select(i -> Primes[i]+Primes[i+6] = Primes[i+2]+Primes[i+4] and Primes[i+1]+Primes[i+7]=Primes[i+3]+Primes[i+5], [$1..nops(Primes)-7])];
# Robert Israel, Sep 20 2017
PROG
(PARI) forprime(p=1, 61000, my(v=primes([p, nextprime(nextprime(nextprime(nextprime(nextprime(nextprime(nextprime(p+1)+1)+1)+1)+1)+1)+1)])); if(v[1]+v[7]==v[3]+v[5] && v[2]+v[8]==v[4]+v[6], print1(p, ", "))) \\ Felix Fröhlich, Sep 20 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 20 2017
STATUS
approved