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!)
A127078 a(0)=1. a(n) = a(n-1) + (product of the earlier terms {among terms a(0) through a(n-1)} which are coprime to n). 1
1, 2, 3, 5, 20, 26, 31, 483631, 225372046, 17570301566444363246, 17570301566489340929, 16272673148565174391333181067098727985892644426731405243329 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..11.

EXAMPLE

The terms of the sequence, among terms a(0) through a(5), which are coprime to 6 are a(0)=1 and a(3)=5. So a(6) = a(5) + 1*5 = 31.

MATHEMATICA

f[l_List] := Append[l, l[[ -1]] + Times @@ Select[l, GCD[ #, Length[l]] == 1 &]]; Nest[f, {1}, 13] (* Ray Chandler, Jan 06 2007 *)

CROSSREFS

Cf. A127077.

Sequence in context: A048826 A321084 A054798 * A184252 A228833 A320950

Adjacent sequences:  A127075 A127076 A127077 * A127079 A127080 A127081

KEYWORD

nonn

AUTHOR

Leroy Quet, Jan 04 2007

EXTENSIONS

Extended by Ray Chandler, Jan 06 2007

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 May 27 21:52 EDT 2020. Contains 334671 sequences. (Running on oeis4.)