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A343330
a(n) is the largest odd positive integer that is abundant and has the same prime signature as A279537(n) or 0 if no such integer exists.
0
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 945, 0, 0, 2205, 0, 0, 2835, 0, 0, 15435, 0, 0, 8505, 0, 0, 108045, 0, 0, 11025, 25515, 0, 46305, 0, 0, 756315, 0, 0, 81675, 76545, 0, 324135, 0, 0, 5294205, 0, 0, 540225, 229635, 0, 2268945, 0, 0, 898425, 37059435, 0, 972405, 0, 3781575, 688905, 0, 0, 15882615, 0
OFFSET
1,17
COMMENTS
Odd abundant numbers k have omega(k) >= 3. The zeros in this sequence come from numbers k having omega(k) < 3 in which case no positive integer with that prime signature exists.
Numbers with omega(k) > 3 are excluded by definition as most such numbers have infinitely many cases for that prime signature in which case no largest element exists.
EXAMPLE
a(17) = 945 as A279537(17) = 120 = 2^(3) * 3^(1) * 5^(1) and has prime signature (3, 1, 1). The largest odd positive integer that has prime signature (3, 1, 1) and is abundant is 945.
CROSSREFS
Sequence in context: A215838 A145493 A271765 * A133814 A104438 A125013
KEYWORD
nonn
AUTHOR
David A. Corneth, Apr 12 2021
STATUS
approved