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%I #17 Jul 18 2022 09:49:02
%S 1,7,14,15,17,29,31,35,59,63,64,71,79,119,120,127,129,143,159,223,239,
%T 241,255,259,260,287,288,319,320,447,479,483,484,511,512,519,521,575,
%U 577,639,641,895,959,960,967,968,969,1023,1025,1039,1043,1044,1151,1152
%N Indices of nonprime terms in A354790.
%H Rémy Sigrist, <a href="/A354791/b354791.txt">Table of n, a(n) for n = 1..5715</a>
%H Rémy Sigrist, <a href="/A354791/a354791.txt">C program</a>
%o (Python)
%o from math import lcm, gcd
%o from itertools import count, islice
%o from collections import deque
%o from sympy import factorint
%o def A354791_gen(): # generator of terms
%o aset, aqueue, c, b, f, i = {1}, deque([1]), 2, 1, True, 1
%o yield 1
%o while True:
%o for m in count(c):
%o if m not in aset and gcd(m,b) == 1 and all(map(lambda n:n<=1,fs:=factorint(m).values())):
%o i += 1
%o if len(fs) > 1:
%o yield i
%o aset.add(m)
%o aqueue.append(m)
%o if f: aqueue.popleft()
%o b = lcm(*aqueue)
%o f = not f
%o while c in aset:
%o c += 1
%o break
%o A354791_list = list(islice(A354791_gen(),30)) # _Chai Wah Wu_, Jul 17 2022
%o (C) See Links section.
%Y Cf. A354790, A354792.
%K nonn
%O 1,2
%A _Michael De Vlieger_ and _N. J. A. Sloane_, Jul 17 2022
%E More terms from _Rémy Sigrist_, Jul 17 2022
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