A175116 A positive integer k is included if d(k) = d(k+1) * d(k+2), where d(k) is the number of divisors of k.

96, 105, 165, 216, 280, 315, 345, 357, 408, 465, 522, 552, 561, 616, 624, 640, 696, 744, 760, 837, 861, 885, 920, 924, 945, 990, 1032, 1056, 1128, 1185, 1281, 1302, 1368, 1386, 1416, 1464, 1560, 1640, 1785, 1830, 1860, 1905, 1950, 2037, 2142, 2184, 2296

Offset

1,1

Comments

Terms calculated by M. F. Hasler.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Transpose[Select[Partition[Range[3000], 3, 1], DivisorSigma[0, First[#]]== DivisorSigma[0, Last[#]]DivisorSigma[0, #[[2]]]&]][[1]]  (* Harvey P. Dale, Apr 08 2011 *)

Crossrefs

Cf. A000005, A175115, A145470.

Sequence in context: A181470 A306104 A257411 * A153484 A060660 A258748

Adjacent sequences: A175113 A175114 A175115 * A175117 A175118 A175119

Keyword

nonn

Author

Leroy Quet, Feb 13 2010

Status

approved