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A354161 Index of A354160(n) in A090252.

%I A354161 #11 Jun 15 2022 16:47:29
%S A354161 15,29,47,59,63,65,121,131,193,239,241,243,255,257,265,387,479,483,
%T A354161 487,489,515,527,529,531,767,775,777,959,961,967,969,977,979,1023,
%U A354161 1031,1055,1059,1063,1143,1551,1553,1555,1921,1923,1935,1937,1939,1951,1953,1955,1959,1961,2047,2063,2064,2111,2113,2119,2127,2288,3071,3073,3105,3107
%N A354161 Index of A354160(n) in A090252.
%H A354161 Michael De Vlieger, <a href="/A354161/b354161.txt">Table of n, a(n) for n = 1..2517</a>
%o A354161 (Python)
%o A354161 from itertools import count, islice
%o A354161 from collections import deque
%o A354161 from math import gcd, lcm
%o A354161 from sympy import factorint
%o A354161 def A354161_gen(): # generator of terms
%o A354161     aset, aqueue, c, b, f, i = {1}, deque([1]), 2, 1, True, 1
%o A354161     while True:
%o A354161         for m in count(c):
%o A354161             if m not in aset and gcd(m,b) == 1:
%o A354161                 i += 1
%o A354161                 if len(fm := factorint(m)) == sum(fm.values()) == 2:
%o A354161                     yield i
%o A354161                 aset.add(m)
%o A354161                 aqueue.append(m)
%o A354161                 if f: aqueue.popleft()
%o A354161                 b = lcm(*aqueue)
%o A354161                 f = not f
%o A354161                 while c in aset:
%o A354161                     c += 1
%o A354161                 break
%o A354161 A354161_list = list(islice(A354161_gen(),25)) # _Chai Wah Wu_, May 31 2022
%Y A354161 Cf. A090252, A354159, A354160, A354162, A354163.
%K A354161 nonn
%O A354161 1,1
%A A354161 _N. J. A. Sloane_, May 30 2022