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A354162 Products of exactly two distinct odd primes in A090252, in order of appearance. 3
21, 55, 85, 57, 161, 319, 217, 481, 205, 731, 517, 159, 1121, 1403, 871, 355, 1241, 869, 2407, 1691, 413, 3007, 2323, 1391, 4033, 565, 5207, 2227, 5891, 6533, 4321, 453, 1007, 623, 4867, 2231, 6161, 2119, 11189, 6401, 12709, 7421, 2159, 9563, 8213, 1507, 15247, 9259, 4031, 12367, 597, 2869, 11183, 1561, 13393, 7099, 3611, 14213, 24823 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Odd terms in A354160. - Chai Wah Wu, May 31 2022
LINKS
PROG
(Python)
from itertools import count, islice
from collections import deque
from math import gcd, lcm
from sympy import factorint
def A354162_gen(): # generator of terms
aset, aqueue, c, b, f = {1}, deque([1]), 2, 1, True
while True:
for m in count(c):
if m not in aset and gcd(m, b) == 1:
if m % 2 and len(fm := factorint(m)) == sum(fm.values()) == 2:
yield m
aset.add(m)
aqueue.append(m)
if f: aqueue.popleft()
b = lcm(*aqueue)
f = not f
while c in aset:
c += 1
break
A354162_list = list(islice(A354162_gen(), 25)) # Chai Wah Wu, May 31 2022
CROSSREFS
Sequence in context: A190664 A144302 A347373 * A180674 A067431 A083676
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 30 2022
STATUS
approved

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Last modified March 1 09:59 EST 2024. Contains 370432 sequences. (Running on oeis4.)