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A124979
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Numbers in A118882 for which 5 is not a divisor.
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2
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169, 221, 289, 338, 377, 442, 481, 493, 533, 578, 629, 676, 689, 697, 754, 793, 841, 884, 901, 949, 962, 986, 1037, 1066, 1073, 1156, 1157, 1189, 1241, 1258, 1261, 1313, 1352, 1369, 1378, 1394, 1417, 1469, 1508, 1513, 1517
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OFFSET
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1,1
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LINKS
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PROG
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(Python)
from itertools import count, islice
from math import prod
from sympy import factorint
def A124979_gen(startvalue=1): # generator of terms >= startvalue
for n in count(max(startvalue, 1)):
f = factorint(n)
if n%5 and 1<int(not any(e&1 for e in f.values())) + (((m:=prod(1 if p==2 else (e+1 if p&3==1 else (e+1)&1) for p, e in f.items()))+((((~n & n-1).bit_length()&1)<<1)-1 if m&1 else 0))>>1):
yield n
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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Further corrections following an observation by P. McNab, by M. F. Hasler, Jul 08 2015
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STATUS
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approved
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