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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