A228961 Smallest sets of 4 consecutive abundant numbers in arithmetic progression. The initial abundant number is listed.

114, 120, 228, 234, 240, 282, 348, 420, 582, 588, 654, 660, 708, 840, 1002, 1008, 1014, 1068, 1122, 1242, 1248, 1254, 1260, 1380, 1434, 1542, 1548, 1674, 1794, 1800, 1908, 1914, 1998, 2094, 2100, 2208, 2214, 2220, 2262, 2268, 2328, 2334, 2340, 2502, 2508

Offset

1,1

Links

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

Example

114, 120, 126, 132 is the smallest set of 4 consecutive abundant numbers in arithmetic progression so 114 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 > 3, AppendTo[a, n - 3*cd]], m = 2; cd = n - z1]; z1 = n], {n, 19, 1000000}]; a

Crossrefs

Cf. A005101, A228433, A228844.

Sequence in context: A138693 A272303 A260213 * A057440 A113537 A352233

Adjacent sequences: A228958 A228959 A228960 * A228962 A228963 A228964

Keyword

nonn

Author

Shyam Sunder Gupta, Nov 10 2013

Status

approved