A355009 Primes in A354975.

2, 47, 173, 317, 409, 967, 3877, 6173, 6449, 14401, 16477, 18257, 28183, 30119, 73561, 76607, 86579, 90227, 92867, 97987, 110777, 112663, 114749, 117671, 121553, 130069, 136033, 141403, 144671, 190891, 205129, 207301, 208283, 216481, 221677, 229199, 235337, 231223, 261347, 265123, 281191, 311473

Offset

1,1

Comments

Primes are in the order in which they appear in A354975, so the sequence is not increasing: for example, a(37) = 235337 > 231223 = a(38).

Links

Robert Israel, Table of n, a(n) for n = 1..1000

Formula

a(n) = A354975(A354972(n)).

Example

a(3) = A354975(15) = 173 is the third member of A354975 that is prime.

Maple

f:= proc(n) local k;
   add(ithprime(n+k) mod ithprime(k), k=1..n)
end proc:
select(isprime, map(f, [$1..1000]);

Mathematica

Block[{nn = 450, a, p}, Do[Set[p[i], Prime[i]], {i, 2 nn}]; Reap[Do[If[PrimeQ[#], Sow[#]] &@ Sum[Mod[p[i + j], p[j]], {j, i}], {i, nn}]][[-1, -1]]] (* Michael De Vlieger, Jun 19 2022 *)

Prog

(PARI) lista(nn) = my(list=List()); for (n=1, nn, if (isprime(p=sum(i=1, n, prime(i+n) % prime(i))), listput(list, p)); ); Vec(list); \\ Michel Marcus, Jun 19 2022
(Python)
from itertools import count, islice
from sympy import prime, isprime
def A355009_gen(): # generator of terms
    return filter(isprime, (sum(prime(i+n) % prime(i) for i in range(1, n+1)) for n in count(1)))
A355009_list = list(islice(A355009_gen(), 5)) # Chai Wah Wu, Jun 20 2022

Crossrefs

Cf. A354972, A354975.

Sequence in context: A142313 A264776 A153213 * A304725 A128822 A226420

Adjacent sequences: A355006 A355007 A355008 * A355010 A355011 A355012

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Jun 15 2022

Status

approved