login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A235368 The smallest number with n representations of the form A*B^A with A, B > 1. 2
8, 648, 344373768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Call a number of the form A*B^A, A&B>1 an ABA number. Then a(n) is the smallest ABA number with n representations of this form.

a(n) exists for every n. For example, a(4) <= k = 2^105*3^70*5^126*7^120, where k (a number of 255 digits) has 4 representations with A = 2, 3, 5, and 7. - Giovanni Resta, Jan 09 2014

LINKS

Table of n, a(n) for n=1..3.

R. Munafo, Generalized Cullen and Woodall Numbers

Giovanni Resta, ABA numbers, Numbers Aplenty

EXAMPLE

a(3) = 344373768 = 8*9^8 = 3*486^3 = 2*13122^2.

CROSSREFS

Cf. A171606, A171607.

Sequence in context: A258385 A267968 A253268 * A247731 A231849 A159621

Adjacent sequences:  A235365 A235366 A235367 * A235369 A235370 A235371

KEYWORD

nonn,bref,more,hard

AUTHOR

Carlos Rivera, Jan 08 2014

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 20 06:18 EDT 2022. Contains 353852 sequences. (Running on oeis4.)