a new sequence

Max maxale at gmail.com
Tue May 16 21:48:19 CEST 2006


On 5/16/06, Max <maxale at gmail.com> wrote:

> Your sequence is a subsequence of A051774.
> Indeed, suppose that n belongs to your sequence. Then there are two
> distinct subsets of divisors of n with equal sums. After removing
> elements that appear in both subsets we still have two non-empty
> subsets with equal sums, say,
> d_1 + ... + d_m = e_1 + ... + e_n
> where all divisors d_1, ..., d_m, e_1, ..., e_n are distinct.
> Without loss of generality we can assume that d_1 is the maximum
> divisor among all divisors in both subsets. In particular, we have e_1
> < d_1, ..., e_n < d_m and
> d_m <= e_1 + ... + e_n
> meaning that n belongs to A051774.

Ops. The last sentence must be
"In particular, we have
e_1 < d_1, ..., e_n < d_1 and d_1 <= e_1 + ... + e_n
meaning that n belongs to A051774."

Taking into account that the new sequence is a subsequence of A051774,
it is interesting to find a sequence forming their set difference.
As Emeric noticed, the first term of this sequence is 175.
Is anybody willing to compute more terms and to submit it to OEIS?

Max






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