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A231628
Smallest sets of 6 consecutive deficient numbers in arithmetic progression. The initial deficient number is listed.
3
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
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
KEYWORD
nonn
AUTHOR
Shyam Sunder Gupta, Nov 11 2013
STATUS
approved