%I #9 Apr 15 2021 22:55:02
%S 173,337,479,727,1399,2447,3727,10859,11897,22349,23857,26267,80963,
%T 105097,112069,170081,191861,243931,276343,284593,613181,665213,
%U 771863,827521,862607,951413,1050449,1158961,1334093,1380259,1435519,1495517,1584983,1660697,1745581,1847861,1929569,2067529
%N Primes of the form p+q*(r+s), where p,q,r,s are consecutive primes.
%C a(n) = p+q*(r+s) where p = A343448(n) and q,r,s are the next three primes after p.
%H Robert Israel, <a href="/A343449/b343449.txt">Table of n, a(n) for n = 1..10000</a>
%e For n = 3, A343448(3) = 11 and the next three primes are 13, 17, 19, so a(3) = 11+13*(17+19) = 479.
%p B:= NULL: q:= 2: r:= 3: s:= 5: count:= 0:
%p while count < 100 do
%p p:= q; q:= r; r:= s; s:= nextprime(s);
%p v:= p+q*(r+s);
%p if isprime(v) then B:= B,v; count:= count+1 fi
%p od:
%p B;
%o (Python)
%o from sympy import isprime, nextprime
%o def aupto(limit):
%o p, q, r, s, alst = 2, 3, 5, 7, []
%o t = p + q*(r+s)
%o while t <= limit:
%o if isprime(t): alst.append(t)
%o p, q, r, s = q, r, s, nextprime(s)
%o t = p + q*(r+s)
%o return alst
%o print(aupto(2067529)) # _Michael S. Branicky_, Apr 15 2021
%Y Cf. A343448.
%K nonn
%O 1,1
%A _J. M. Bergot_ and _Robert Israel_, Apr 15 2021
|