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A175115 An integer k, k >=3, is included if d(k) = d(k-1)*d(k-2), where d(k) is the number of divisors of k. 2
3, 24, 120, 150, 195, 216, 294, 312, 399, 440, 459, 525, 540, 558, 570, 615, 630, 663, 693, 696, 744, 759, 774, 858, 999, 1032, 1095, 1125, 1152, 1176, 1239, 1350, 1455, 1470, 1494, 1608, 1624, 1659, 1664, 1710, 1725, 1734, 1785, 1860, 1880, 1896, 1914 (list; graph; refs; listen; history; text; internal format)
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[2000], 3, 1], DivisorSigma[0, Last[#]] == DivisorSigma[0, First[#]] * DivisorSigma[0, #[[2]]]&]][[1]] + 2 (* Amiram Eldar, Jul 17 2019 after Harvey P. Dale at A175116 *)

CROSSREFS

Cf. A000005, A175116, A145469.

Sequence in context: A139031 A065692 A127520 * A301812 A268633 A324065

Adjacent sequences:  A175112 A175113 A175114 * A175116 A175117 A175118

KEYWORD

nonn

AUTHOR

Leroy Quet, Feb 13 2010

STATUS

approved

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Last modified May 25 11:07 EDT 2020. Contains 334592 sequences. (Running on oeis4.)