

A188263


Odd abundant numbers whose abundancy is closer to 2 than any smaller odd abundant number.


10



945, 2205, 7425, 8415, 8925, 31815, 32445, 351351, 442365, 14571585, 20355825, 20487159, 78524145, 159030135, 1756753845, 2586415095, 82014476355, 93128205975, 125208115065, 127595519865, 154063853475, 394247024535, 948907364895
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

The abundancy of a number n is defined as sigma(n)/n. Abundant numbers have an abundancy greater than 2. All these numbers must be odd primitive abundant numbers, A006038.
These numbers might be considered the opposite of A119239, which has odd numbers whose abundancy increases. This sequence has terms in common with A171929. A similar sequence for deficient numbers is A188597.
These are odd numbers that are barely abundant. See A071927 for the even version.


LINKS



MATHEMATICA

k = 1; minDiff = 1; Table[k = k + 2; While[abun = DivisorSigma[1, k]/k; abun  2 > minDiff  abun < 2, k = k + 2]; minDiff = abun  2; k, {10}]


CROSSREFS

Cf. A171929 (odd numbers whose abundancy is closer to 2 than any smaller odd number)


KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



