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

Author

Shyam Sunder Gupta, Nov 10 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Cf. A005101, A228433.

Programs

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