A349869 Nobly deficient numbers (A349759) that are not deficient numbers (A005100).

36, 48, 100, 112, 144, 162, 192, 196, 208, 324, 400, 448, 576, 784, 832, 900, 1296, 1458, 1600, 1764, 1936, 1984, 2304, 2368, 2500, 2704, 2752, 2916, 3072, 3136, 3600, 3904, 4288, 4356, 4624, 4672, 4900, 5184, 5776, 6084, 6208, 6400, 6976, 7056, 7168, 7744, 8100

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

36 is a term since it is not deficient, A000203(36) = 91 > 2*36 = 72, and both A000005(36) = 9 and A000203(36) = 91 are deficient.

Mathematica

defQ[n_] := DivisorSigma[1, n] < 2*n; nobDefQ[n_] := And @@ defQ /@ DivisorSigma[{0, 1}, n]; Select[Range[10^4], !defQ[#] && nobDefQ[#] &]

Crossrefs

Intersection of A023196 and A349759.

Cf. A000005, A000203, A005100, A349868.

Sequence in context: A357606 A348274 A033701 * A260920 A132956 A260015

Adjacent sequences: A349866 A349867 A349868 * A349870 A349871 A349872

Keyword

nonn

Author

Amiram Eldar, Dec 03 2021

Status

approved