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!)
A080798 Largest prime factor of 3^n-2. 3
7, 5, 79, 241, 727, 23, 937, 19681, 431, 499, 4703, 8093, 40193, 2869781, 483671, 94747, 4657, 232452293, 498112057, 2812679, 31381059607, 3765727153, 1364071, 44594137339, 125231, 13170403, 5353801183, 4159349, 46050353857 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Hugo Pfoertner, Table of n, a(n) for n = 2..210

FORMULA

a(n) = A006530(A058481(n)). - Michel Marcus, Jul 12 2019

PROG

(PARI) a(n) = vecmax(factor(3^n-2)[, 1]); \\ Michel Marcus, Jul 12 2019

(MAGMA) [Max(PrimeDivisors(3^n-2)):n in [2..30]]; // Marius A. Burtea, Jul 12 2019

CROSSREFS

Cf. A014224, A014232, A080443, A080892.

Cf. A006530, A058481.

Sequence in context: A038271 A329008 A005692 * A007553 A294474 A248277

Adjacent sequences:  A080795 A080796 A080797 * A080799 A080800 A080801

KEYWORD

nonn

AUTHOR

Hugo Pfoertner, Mar 25 2003

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 04:09 EDT 2021. Contains 345452 sequences. (Running on oeis4.)