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A351533
Odd numbers k that are multiples of 3 and for which sigma(k) is congruent to 2 modulo 4.
2
45, 117, 153, 261, 333, 369, 405, 477, 549, 657, 801, 873, 909, 981, 1017, 1053, 1233, 1341, 1377, 1413, 1557, 1629, 1737, 1773, 2061, 2097, 2169, 2205, 2313, 2349, 2421, 2493, 2529, 2637, 2817, 2853, 2925, 2997, 3033, 3141, 3177, 3321, 3357, 3501, 3573, 3609, 3645, 3681, 3789, 3825, 3897, 4041, 4113, 4149, 4293
OFFSET
1,1
MATHEMATICA
Select[3*Range[1, 1400, 2], Mod[DivisorSigma[1, #], 4] == 2 &] (* Amiram Eldar, Feb 13 2022 *)
PROG
(PARI) isA351533(n) = ((n%2) && !(n%3) && (2 == (sigma(n)%4)));
CROSSREFS
Intersection of A008585 and A191218. Complement of A351535 in A191218.
Cf. A351534 (subsequence).
Sequence in context: A044613 A039528 A228058 * A074770 A348939 A370914
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 13 2022
STATUS
approved