

A333041


Odd numbers m such that sigma(m) > sigma(m1).


0



3, 63, 75, 135, 147, 195, 255, 315, 399, 405, 459, 483, 495, 525, 555, 567, 615, 627, 663, 675, 693, 735, 759, 765, 795, 819, 855, 915, 945, 975, 999, 1035, 1095, 1125, 1155, 1215, 1239, 1287, 1323, 1395, 1455, 1515, 1539, 1575, 1647, 1659, 1683, 1755, 1785, 1815, 1827, 1845, 1875
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OFFSET

1,1


COMMENTS

The odd terms of A333038 [sigma(m) <= sigma(m1)] represent about 95% of the data, so the odd integers that do not satisfy this relation are proposed here.
Except for 3, there are no prime powers in this sequence.
It appears that most of the terms are divisible by 3; the two smallest exceptions are 13475 and 17255 (see A323726).
Odd (and even) numbers such that sigma(m) = sigma(m1) are in A231546.


LINKS



EXAMPLE

sigma(63) = 1+3+7+9+21+63 = 104 > sigma(62) = 1+2+31+62=96 and 63 is in the sequence.
sigma(77) = 1+7+11+77 = 96 < sigma(76) = 1+2+4+19+38+76 = 140 and 77 is not a term.


MATHEMATICA

Select[2 * Range[1000] + 1, DivisorSigma[1, #] > DivisorSigma[1, #  1] &] (* Amiram Eldar, Apr 14 2020 *)


PROG



CROSSREFS

Apart from the first term, a subsequence of A334117.


KEYWORD

nonn


AUTHOR



STATUS

approved



