login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A175459 a(1)=4. a(n) = a(n-1) + n, if a(n-1)+n is composite. Otherwise a(n) = a(n-1)*n. 1
4, 6, 9, 36, 180, 186, 1302, 1310, 11790, 11800, 11811, 11823, 11836, 11850, 11865, 11881, 11898, 11916, 11935, 11955, 11976, 11998, 12021, 12045, 12070, 12096, 12123, 12151, 12180, 12210, 378510, 378542, 378575, 378609, 378644, 378680 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Each term is composite.

LINKS

Table of n, a(n) for n=1..36.

MAPLE

A175459 := proc(n) option remember; if n =1 then 4; else if isprime( procname(n-1)+n) then procname(n-1)*n; else procname(n-1)+n ; end if; end if; end proc:

seq(A175459(n), n=1..120) ; # R. J. Mathar, May 28 2010

CROSSREFS

Sequence in context: A291717 A303699 A292153 * A257652 A107665 A085733

Adjacent sequences:  A175456 A175457 A175458 * A175460 A175461 A175462

KEYWORD

nonn

AUTHOR

Leroy Quet, May 20 2010

EXTENSIONS

More terms from R. J. Mathar, May 28 2010

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 June 25 17:47 EDT 2019. Contains 324353 sequences. (Running on oeis4.)