A078095 Numbers k such that Omega(k) = Omega(k-1) + Omega(k-2) + Omega(k-3) + Omega(k-4). (Omega(k) denotes the number of prime factors of k, counting multiplicity).

1440, 2560, 2880, 3456, 3584, 5760, 6720, 7168, 8192, 8448, 9600, 10080, 10368, 10800, 12150, 12480, 13440, 14000, 15120, 18144, 21120, 21384, 22400, 25088, 25920, 26880, 28320, 30240, 31104, 31680, 34992, 35840, 38400, 39168, 39366

Offset

1,1

Links

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

Example

a(1) = 1440 is a term because Omega(1440) = 8 = Omega(1439) + Omega(1438) + Omega(1437) + Omega(1436) = 1 + 2 + 2 + 3 = 8.

Prog

(Magma) f:=func<n|&+[p[2]: p in Factorization(n)]>; [k:k in [6..40000]| f(k) eq f(k-1)+ f(k-2)+f(k-3)+f(k-4)]; // Marius A. Burtea, Feb 19 2020

Crossrefs

Cf. A001222.

Sequence in context: A063846 A252186 A179691 * A157508 A061221 A238041

Adjacent sequences: A078092 A078093 A078094 * A078096 A078097 A078098

Keyword

nonn

Author

Shyam Sunder Gupta, Dec 01 2002

Status

approved