OFFSET
1,1
COMMENTS
a(1045) has 1003 digits. - Michael S. Branicky, Apr 30 2025
REFERENCES
Paolo Ribenboim, "The New Book of Prime Number Records", 1996, ISBN 0-387-94457-5 Page 5
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..1044
R. Mestrovic, Euclid's theorem on the infinitude of primes: a historical survey of its proofs (300 BC--2012) and another new proof, arXiv preprint arXiv:1202.3670 [math.HO], 2012-2018. - From N. J. A. Sloane, Jun 13 2012
Peter Schorn, Schorn's Proof
www.mathematic.de, Schorn's proof
FORMULA
For each n >= 1, add all n!*i+1, where 1 <= i <= n and n!*i+1 is a prime. [Clarified by Michael S. Branicky, Apr 30 2025.]
EXAMPLE
6!*3+1 = 2161 is prime and is a term.
MATHEMATICA
lst={}; Do[lst=Join[lst, Select[n!Range[n]+1, PrimeQ]], {n, 12}]; lst (* T. D. Noe, Nov 02 2006 *)
PROG
(Python)
from math import factorial
from gmpy2 import is_prime
from itertools import count, islice
def agen():
for n in count(1):
f = factorial(n)
yield from (t for i in range(1, n+1) if is_prime(t:=f*i+1))
print(list(islice(agen(), 32))) # Michael S. Branicky, Apr 30 2025
CROSSREFS
KEYWORD
nonn
AUTHOR
Karsten Meyer, Mar 12 2005; extended Jun 08 2005
EXTENSIONS
Corrected by T. D. Noe, Nov 02 2006
STATUS
approved
