A145470 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.

12, 30, 42, 45, 56, 66, 112, 220, 261, 282, 294, 297, 308, 342, 364, 390, 416, 477, 492, 513, 516, 532, 536, 555, 567, 572, 580, 620, 621, 632, 651, 700, 705, 768, 777, 786, 795, 812, 832, 836, 860, 880, 884, 891, 897, 906, 957, 975, 976, 981, 992, 1000, 1005

Offset: 1

Author

Leroy Quet, Oct 11 2008

Keywords

• nonn

Links

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

Crossrefs

Cf. A000005, A145469, A175116.

Programs

Mathematica

Transpose[Select[Partition[Range[1010], 3, 1], DivisorSigma[0, First[#]] == DivisorSigma[0, Last[#]] + DivisorSigma[0, #[[2]]]&]][[1]] (* Amiram Eldar, Jul 17 2019 after Harvey P. Dale at A175116 *)

Extensions

Extended by Ray Chandler, Oct 27 2008