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!)
A147801 Minimal value of A007947(m(3^n-m)) with m coprime to 3. 5
2, 2, 10, 10, 22, 110, 278, 238, 1054, 1342, 11066, 6118, 18734, 107030, 557270, 163030 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Related to the abc conjecture. The minima are reached for m values given in A147802. See also A143702, A147800 (2^n, 5^n analogs) and A147298 (general case).

All terms of this sequence are even, so one could also consider A147801/2 = 1, 1, 5, 5, 11, 55, 139, 119, 527, 671, 5533, 3059, 9367, 53515, 278635, 81515,...

LINKS

Table of n, a(n) for n=1..16.

PROG

(PARI) A147801(n, p=3)={local(m=n=p^n); for(a=1, (n-1)\2, a%p|next; A007947(n-a)*A007947(a)<m|next; m=A007947((n-a)*a)); m}

CROSSREFS

Cf. A007947, A147298, A143702 (analog for 2^n), A147800 (analog for 5^n).

Sequence in context: A249152 A216708 A032005 * A263053 A066965 A066966

Adjacent sequences:  A147798 A147799 A147800 * A147802 A147803 A147804

KEYWORD

more,nonn

AUTHOR

M. F. Hasler, Nov 13 2008

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 April 4 05:34 EDT 2020. Contains 333212 sequences. (Running on oeis4.)