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A220432
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Numbers not divisible by 2, 3 or any prime of the form 4x^2+2xy+7y^2 (see A219908).
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2
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1, 5, 11, 17, 19, 23, 25, 29, 31, 37, 41, 43, 47, 53, 55, 59, 61, 67, 71, 83, 85, 89, 95, 97, 101, 103, 107, 109, 113, 115, 121, 125, 127, 131, 137, 139, 145, 149, 155, 157, 167, 173, 179, 181, 185, 187, 191, 197, 199, 205, 209, 215, 223, 227, 229, 233, 235
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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Note that Jagy omitted 19.
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LINKS
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W. C. Jagy, Problem 11539, Amer. Math. Monthly, 119 (2012), 884-885.
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PROG
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(Haskell)
a220432 n = a220432_list !! (n-1)
a220432_list = filter (\x -> null $
intersect (a027748_row x) (takeWhile (<= x) a219908_list)) a007310_list
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CROSSREFS
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Cf. a027748, subsequence of A007310.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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