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A375028
Primes in A374965 in order of their occurrence.
5
3, 19, 103, 463, 751, 283, 331, 103423, 313, 2671, 1543, 1783, 3823, 68863, 20287, 733, 757, 407896063, 2083, 1093, 2251, 1153, 2371, 1213, 2467, 41023, 2707, 2803, 1453, 119909605576788675546376149602926591, 98238463, 25903, 3405823, 3590143, 3733, 14983, 7603, 7723, 15607, 65306623, 537343, 69151, 3859801644442622798122887215978426484283282692686288680974641672159756287
OFFSET
1,1
COMMENTS
Sequences A050412 and A052333 suggest that it is possible that the present sequence has only finitely many terms. - N. J. A. Sloane, Jul 29 2024
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..289 [This b-file ends with a(289) = 838951. Thanks to the work of Lucas A. Brown (see A050412), we can now say that the next term a(290) is the 102410-digit prime 104917*2^340181 - 1. Of course this is too large to include in a b-file. - N. J. A. Sloane, Jul 31 2024]
N. J. A. Sloane, A Nasty Surprise in a Sequence and Other OEIS Stories, Experimental Mathematics Seminar, Rutgers University, Oct 10 2024, Youtube video; Slides [Mentions this sequence]
MATHEMATICA
nxt[{n_, a_}]:={n+1, If[!PrimeQ[a], 2a+1, Prime[n+1]-1]}; Select[NestList[nxt, {1, 1}, 999][[;; , 2]], PrimeQ]
PROG
(Python)
from itertools import islice
from sympy import isprime, nextprime
def A375028_gen(): # generator of terms
a, p = 1, 3
while True:
if isprime(a):
yield a
a = p-1
else:
a = (a<<1)+1
p = nextprime(p)
A375028_list = list(islice(A375028_gen(), 30)) # Chai Wah Wu, Jul 29 2024
CROSSREFS
A373799 gives the indices where the primes appear in A374965.
A373804 gives the primes sorted into increasing or5der.
Sequence in context: A095120 A304625 A373804 * A151539 A305555 A323919
KEYWORD
nonn
AUTHOR
STATUS
approved