A228844 Smallest sets of 3 consecutive abundant numbers in arithmetic progression. The initial abundant number is listed.

24, 42, 80, 100, 104, 114, 120, 126, 144, 162, 180, 196, 200, 220, 228, 234, 240, 246, 272, 282, 288, 304, 324, 348, 350, 364, 392, 402, 420, 426, 440, 460, 504, 572, 582, 588, 594, 608, 616, 624, 640, 654, 660, 666, 684, 700, 708, 714, 728, 736, 740, 786

Offset

1,1

Links

Shyam Sunder Gupta, Table of n, a(n) for n = 1..5000

Example

24, 30, 36 is the smallest set of 3 consecutive abundant numbers in arithmetic progression so 24 is in the list.

Mathematica

AbundantQ[n_] := DivisorSigma[1, n] > 2 n; m = 2; z1 = 18; cd = 6; a = {}; Do[If[AbundantQ[n], If[n - z1 == cd, m = m + 1; If[m > 2, AppendTo[a, n - 2*cd]], m = 2; cd = n - z1]; z1 = n], {n, 19, 1000000}]; a

Crossrefs

Cf. A005101, A228433.

Sequence in context: A063702 A074975 A077095 * A111948 A039411 A043234

Adjacent sequences: A228841 A228842 A228843 * A228845 A228846 A228847

Keyword

nonn

Author

Shyam Sunder Gupta, Nov 10 2013

Status

approved