possiby double

[Andrew Plewe]

70 and 90 are unique to 122906, thus it's not the same as the other two. 
I would classify A042965 and A074227 as possible duplicates as well 
after correcting for offset differences.

    -Andrew Plewe-

Peter Pein wrote:
> I didn't follow the double hunting in detail. So please forgive me, if this
> has already been sent:
>
> A042965 seems to be the same as A122906 and A074227 and these could
> additionally be described in words as nonnegative integers, which are a
> difference of squares.
>
> P²
>
>   




Neil,

The descriptions would be clearer if you omit the comma before "which", to
make them:

Triangular numbers which are differences of nonnegative cubes.

and similarly for the other.

Jonathan Sondow


On 6/13/07 2:04 AM N. J. A. Sloane wrote:

> Peter, i will add those 2 sequences - they will be A129965 and A129966
> 
> Neil
> 




With all the talk lately about duplicate sequences, I have an idea.

Maybe after a sequence is submitted via the on-line form, the submitted 
duplicate. The submitter would then receive a message, if appropriate, 
possibly be these/this sequence(s):". And then a list of possible 
duplicates is given. Then the website would ask, "Do you still wish to 

When checking sequences for duplication, it would be a good idea if the 
OEIS computer skips the first term or two, since sequences can often be 
the same except for the first couple terms.

And there should be a message if the sequence matches another sequence 
already in the database for the terms given, but the sequence already in 
the database does not contain as many terms as the newly submitted 
A message like, "This sequence may be an extension of this/these 

Just an idea. Feel free to ignore it.

Thanks,
Leroy Quet