login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A304358
Primes that are the sum of three consecutive primes == 3 (mod 4).
3
37, 53, 73, 97, 149, 173, 197, 233, 293, 337, 397, 421, 509, 569, 601, 661, 1129, 1181, 1289, 1373, 1409, 1433, 1493, 1721, 1949, 2137, 2281, 2633, 2677, 2777, 2833, 3041, 3089, 3121, 3581, 3769, 3821, 3853, 3877, 3929, 4013, 4093, 4289, 4337, 4357, 4441, 4597, 4733, 4909, 4957, 5381, 5501, 5657
OFFSET
1,1
LINKS
EXAMPLE
The first three primes == 3 (mod 4) are 3, 7, 11, but 3+7+11=21 is not prime.
The second, third and fourth primes == 3 (mod 4) are 7, 11, 19, and 7+11+19=37 is prime, so a(1)=37.
MAPLE
N:= 2000: # to use primes <= N that == 1 (mod 4)
P:= select(isprime, [seq(i, i=1..N, 4)]):
select(isprime, P[1..-3]+P[2..-2]+P[3..-1]);
MATHEMATICA
M = 2000;
P = Select[Range[3, M, 4], PrimeQ];
Select[P[[1;; -3]] + P[[2;; -2]] + P[[3;; -1]], PrimeQ] (* Jean-François Alcover, Apr 27 2019, from Maple *)
CROSSREFS
Cf. A002145, A304356. Subset of A002144.
Sequence in context: A101938 A060330 A302720 * A214755 A101940 A330339
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, May 11 2018
STATUS
approved