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A220432
Numbers not divisible by 2, 3 or any prime of the form 4x^2+2xy+7y^2 (see A219908).
2
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
OFFSET
1,2
COMMENTS
Note that Jagy omitted 19.
LINKS
W. C. Jagy, Problem 11539, Amer. Math. Monthly, 119 (2012), 884-885.
PROG
(Haskell)
a220432 n = a220432_list !! (n-1)
a220432_list = filter (\x -> null $
intersect (a027748_row x) (takeWhile (<= x) a219908_list)) a007310_list
-- Reinhard Zumkeller, Dec 15 2012
CROSSREFS
Cf. A027748, subsequence of A007310.
Sequence in context: A077130 A119754 A239127 * A266420 A317048 A081717
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 15 2012
EXTENSIONS
Data fixed and extended by Reinhard Zumkeller, Dec 15 2012
STATUS
approved