login
A339953
Primes of the form (p + 2*q + r)/6 where p, q and r are consecutive primes.
2
5, 7, 11, 13, 29, 47, 67, 71, 73, 83, 131, 151, 233, 307, 461, 467, 479, 571, 577, 587, 613, 619, 643, 727, 853, 947, 953, 967, 991, 1063, 1093, 1231, 1249, 1291, 1297, 1427, 1489, 1493, 1867, 1871, 1879, 2017, 2083, 2111, 2251, 2309, 2311, 2473, 2749, 2753, 2767, 3011, 3089, 3191, 3313, 3691
OFFSET
1,1
LINKS
FORMULA
a(n) = (A151799(A339954(n))+2*A339954(n)+A151800(A339954(n)))/6.
EXAMPLE
a(3) = 11 is a term because 13, 17, 19 are consecutive primes with (13+2*17+19)/6 = 11 and 11 is prime.
MAPLE
q:= 2: r:= 3:
count:= 0: R:= NULL:
while count < 100 do
p:= q; q:= r; r:= nextprime(r);
w:= (p+2*q+r)/6;
if w::integer and isprime(w) then
count:= count+1; R:= R, w;
fi
od:
R;
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Dec 24 2020
STATUS
approved