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A140546
Primes p such that neither p - 6 nor p + 6 is prime.
5
2, 3, 71, 127, 139, 149, 181, 211, 241, 281, 293, 349, 397, 401, 409, 419, 421, 431, 479, 487, 491, 499, 521, 523, 617, 631, 643, 661, 673, 691, 701, 709, 719, 743, 761, 769, 773, 787, 797, 809, 811, 839, 907, 911, 919, 929, 937, 967, 1009, 1021, 1031, 1049
OFFSET
1,1
LINKS
MAPLE
isA140546 := proc(n)
if isprime(n) then
if isprime(n+6) or isprime(n-6) then
false;
else
true;
end if;
else
false ;
end if;
end proc:
A140546 := proc(n)
option remember;
local a;
if n = 1 then
2 ;
else
a := nextprime(procname(n-1)) ;
while true do
if isA140546(a) then
return a;
else
a := nextprime(a) ;
end if;
end do:
end if;
end proc:
seq(A140546(n), n=1..80) ; # R. J. Mathar, Jun 10 2024
CROSSREFS
Cf. A136207 (complement)
Sequence in context: A115892 A290329 A145531 * A234237 A276197 A042233
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Corrected and extended by Charles R Greathouse IV, Mar 25 2010
STATUS
approved