login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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). 1
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 08:19 EDT 2021. Contains 348066 sequences. (Running on oeis4.)