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A349870
Numbers k such that k and k+1 are both nobly abundant numbers (A349758).
2
735, 819, 1035, 1196, 1274, 1275, 1449, 1665, 1700, 1924, 1925, 1952, 1988, 2204, 2324, 2331, 2540, 2655, 2960, 2975, 3068, 3195, 3267, 3324, 3339, 3380, 3549, 3555, 3626, 3717, 4004, 4059, 4164, 4220, 4235, 4256, 4556, 4563, 4598, 4599, 4635, 4655, 4675, 4719
OFFSET
1,1
LINKS
EXAMPLE
735 is a term since 735 and 736 are both nobly abundant numbers: A000005(735) = A000005(736) = 12, A000203(735) = 1368 and A000203(736) = 1512 are all abundant numbers.
MATHEMATICA
abQ[n_] := DivisorSigma[1, n] > 2*n; nobAbQ[n_] := And @@ abQ /@ DivisorSigma[{0, 1}, n]; Select[Range[50000], nobAbQ[#] && nobAbQ[# + 1] &]
CROSSREFS
Subsequence of A349758.
Sequence in context: A025356 A025348 A126556 * A174456 A306474 A250053
KEYWORD
nonn
AUTHOR
Amiram Eldar, Dec 03 2021
STATUS
approved