Template:Sequence of the Day for September 23

Intended for: September 23, 2012

Timetable

• First draft entered by Alonso del Arte on September 18, 2011 ✓
• Draft reviewed by Daniel Forgues on September 22, 2012 ✓
• Draft to be approved by August 23, 2012 ✓

Yesterday's SOTD * Tomorrow's SOTD

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A005231: Odd abundant numbers.

{ 945, 1575, 2205, 2835, 3465, 4095, 4725, ... }

Yes, the very first abundant number to be odd is 945, the 232nd abundant number! The first abundant number is even, namely, 12.

No, the odd abundant numbers are not all divisible by 3 or 5, e.g.

• The first odd abundant number not divisible by 5 is 81081, this being the 175th odd abundant number (and the ?th abundant number).
• The first odd abundant number not divisible by 3 is 5391411025, this being the ?th odd abundant number (and the ?th abundant number).
• The first odd abundant number not divisible by neither 3 nor 5 is 20169691981106018776756331, this being the ?th odd abundant number (and the ?th abundant number).