A231628 Smallest sets of 6 consecutive deficient numbers in arithmetic progression. The initial deficient number is listed.

2987, 4727, 9723, 18843, 22983, 30543, 35147, 39947, 45047, 50463, 55787, 56807, 58055, 58779, 69183, 78047, 81947, 85743, 101147, 106143, 108255, 109247, 117123, 134087, 139743, 139803, 152567, 171287, 174347, 175907, 182643, 189767, 197027, 199803, 202127

Offset

1,1

Links

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

Example

2987, 2989, 2991, 2993, 2995, 2997 is the smallest set of 6 consecutive deficient numbers in arithmetic progression so 2987 is in the list.

Mathematica

DefQ[n_] := DivisorSigma[1, n] < 2 n; m = 2; z1 = 2; cd = 1; a = {}; Do[If[DefQ[n], If[n - z1 == cd, m = m + 1; If[m > 5, AppendTo[a, n - 5*cd]], m = 2; cd = n - z1]; z1 = n], {n, 3, 1000000}]; a

Crossrefs

Cf. A005100, A231623, A228963, A231624, A231625, A231626.

Sequence in context: A365258 A186866 A252571 * A231623 A349063 A108926

Adjacent sequences: A231625 A231626 A231627 * A231629 A231630 A231631

Keyword

nonn

Author

Shyam Sunder Gupta, Nov 11 2013

Status

approved