[seqfan] Re: Help needed

[Andrew Weimholt]

On 1/27/10, Artur <grafix at csl.pl> wrote:
> Dear Seqfans,
>  Who is able to find rule for pairs (n,x)
>  {{5, 483}, {6, 667}, {7, 899}, {8, 1155}, {9, 1443}, {10, 1763}, {11,
>  2091}}
>  a(5)=482, a(6)=667, ...
>  another words sequence is 483, 667, 899, 1155, 1443, 1763, 2091 and
>  offset is 5

here's another possibility...

These are differences of squares...

483 = 22^2 - 1^2
667 = 26^2 - 3^2
899 = 30^2 - 1^2
1155 = 34^2 - 1^2
1443 = 38^2 - 1^2
1763 = 42^2 - 1^2
2091 = 46^2 - 5^2

a(n) = (4n+2)^2 - b(n)^2

where b(n) = ... 1, 3, 1, 1, 1, 1, 5, ...

Andrew