OFFSET
1,1
COMMENTS
So far no composite numbers have been found in this sequence. There are no pseudoprimes up to 2^64 in this sequence, so a composite term in this sequence has to exceed 18446744066047760377.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
Jonas Kaiser, On the relationship between the Collatz conjecture and Mersenne prime numbers, arXiv:1608.00862 [math.GM], 2016.
MATHEMATICA
k = 119; lst = {}; While[k < 12000, If[ PowerMod[{2, 3, 5}, (k - 1)/2, k] == {1, 1, 1}, AppendTo[lst, k]]; k += 120]; lst (* Robert G. Wilson v, Feb 11 2018 *)
PROG
(PARI) is(n) = n%120==119 && Mod(2, n)^((n-1)\2)==1 && Mod(3, n)^((n-1)\2)==1 && Mod(5, n)^((n-1)\2)==1
(Python)
A294092_list, k, m = [], 119, 59
while len(A294092_list) < 10000:
if pow(2, m, k) == 1 and pow(3, m, k) == 1 and pow(5, m, k) == 1:
A294092_list.append(k)
k += 120
m += 60 # Chai Wah Wu, Feb 09 2018
(GAP) Filtered([1..14000], n->n mod 120=119 and 2^((n-1)/2) mod n =1 and 3^((n-1)/2) mod n =1 and 5^((n-1)/2) mod n =1); # Muniru A Asiru, Feb 15 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonas Kaiser, Feb 09 2018
EXTENSIONS
More terms from Chai Wah Wu, Feb 10 2018
STATUS
approved