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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A134858 Numbers that can be written as (a^2-1)(b^2-1) in five or more distinct ways. 2
588107520, 67270694400, 546939993600, 2128050512640, 37400697734400, 5566067918611200 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Subsequence of A134856 and A134857.

Depending on the interpretation of A057535, this is either the same or a supersequence of A057535. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 16 2009]

The next term (if exists) is greater than 2^70.

LINKS

MathPages, Numbers Expressible As (a^2-1)(b^2-1).

EXAMPLE

588107520 = (13^2-1)(1871^2-1) = (17^2-1)(1429^2-1) = (55^2-1)(441^2-1) = (79^2-1)(307^2-1) = (129^2-1)(188^2-1).

CROSSREFS

Cf. A134856, A134857.

Sequence in context: A186961 A032755 A057535 * A145277 A184216 A123705

Adjacent sequences:  A134855 A134856 A134857 * A134859 A134860 A134861

KEYWORD

hard,more,nonn

AUTHOR

Herman Beeksma (herman(AT)beeksma.nl), Nov 13 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 20:06 EST 2012. Contains 205955 sequences.