OFFSET
1,1
COMMENTS
a(n) == 0 mod 120 (see comment in A163573). - Chai Wah Wu, Nov 30 2016
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10001
MATHEMATICA
Select[Range[920000], AllTrue[{#+1, (#+2)/2, (#+3)/3, (#+4)/4}, PrimeQ]&] (* Harvey P. Dale, Aug 08 2021 *)
PROG
(Python)
from sympy import prime, isprime
A278585_list = [4*q-4 for q in (prime(i) for i in range(1, 10000)) if isprime(4*q-3) and isprime(2*q-1) and (not (4*q-1) % 3) and isprime((4*q-1)//3)] # Chai Wah Wu, Nov 30 2016
(PARI) is(k)=k%120==0 && isprime(k+1) && isprime(k/2+1) && isprime(k/3+1) && isprime(k/4+1) \\ Charles R Greathouse IV, Dec 03 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 30 2016
STATUS
approved