login
A228844
Smallest sets of 3 consecutive abundant numbers in arithmetic progression. The initial abundant number is listed.
7
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
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
Sequence in context: A063702 A074975 A077095 * A111948 A039411 A043234
KEYWORD
nonn
AUTHOR
Shyam Sunder Gupta, Nov 10 2013
STATUS
approved