A078093 Numbers k such that Omega(k) = Omega(k+1) + Omega(k+2) + Omega(k+3). (Omega(k) denotes the number of prime factors of k, counting multiplicity.)

64, 176, 216, 280, 288, 320, 336, 352, 384, 400, 416, 432, 480, 500, 560, 616, 704, 720, 756, 784, 800, 840, 936, 960, 1024, 1040, 1056, 1080, 1120, 1184, 1216, 1260, 1360, 1380, 1400, 1440, 1458, 1512, 1656, 1776, 1820, 1836, 1856, 1904, 1944, 1980

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(2)=176 is a term because Omega(176) = 5 = Omega(177) + Omega(178) + Omega(179) = 2 + 2 + 1 = 5.

Mathematica

Position[Partition[PrimeOmega[Range[2000]], 4, 1], _?(#[[1]]==Total[ Rest[ #]]&), 1, Heads->False]//Flatten (* Harvey P. Dale, Apr 16 2018 *)

Crossrefs

Cf. A001222.

Sequence in context: A228666 A209379 A203448 * A209371 A317763 A318342

Adjacent sequences: A078090 A078091 A078092 * A078094 A078095 A078096

Keyword

nonn

Author

Shyam Sunder Gupta, Dec 01 2002

Status

approved