VOOZH about

URL: https://oeis.org/A343449

⇱ A343449 - OEIS

login
A343449
Primes of the form p+q*(r+s), where p,q,r,s are consecutive primes.
2
173, 337, 479, 727, 1399, 2447, 3727, 10859, 11897, 22349, 23857, 26267, 80963, 105097, 112069, 170081, 191861, 243931, 276343, 284593, 613181, 665213, 771863, 827521, 862607, 951413, 1050449, 1158961, 1334093, 1380259, 1435519, 1495517, 1584983, 1660697, 1745581, 1847861, 1929569, 2067529
OFFSET
1,1
COMMENTS
a(n) = p+q*(r+s) where p = A343448(n) and q,r,s are the next three primes after p.
LINKS
EXAMPLE
For n = 3, A343448(3) = 11 and the next three primes are 13, 17, 19, so a(3) = 11+13*(17+19) = 479.
MAPLE
B:= NULL: q:= 2: r:= 3: s:= 5: count:= 0:
while count < 100 do
p:= q; q:= r; r:= s; s:= nextprime(s);
v:= p+q*(r+s);
if isprime(v) then B:= B, v; count:= count+1 fi
od:
B;
PROG
(Python)
from sympy import isprime, nextprime
def aupto(limit):
p, q, r, s, alst = 2, 3, 5, 7, []
t = p + q*(r+s)
while t <= limit:
if isprime(t): alst.append(t)
p, q, r, s = q, r, s, nextprime(s)
t = p + q*(r+s)
return alst
print(aupto(2067529)) # Michael S. Branicky, Apr 15 2021
CROSSREFS
Cf. A343448.
Sequence in context: A241045 A241046 A142206 * A142004 A047986 A096703
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Apr 15 2021
STATUS
approved