[seqfan] Triangular numbers, such that the difference of theirs two (not-equal) largest prime factors is also (smaller) triangular number
Alexander Povolotsky
apovolot at gmail.com
Tue Sep 29 17:27:10 CEST 2009
Hi,
Consider sequence(s?) of the triangular numbers, such that the
difference of theirs two (not-equal - with the exclusion for "factors"
of 1 ) largest prime (or 1 - only when it comes to deal with the
"factors" of 1 ) factors is producing also (but of course smaller)
triangular number
Going backwards (in descending order) I found one such (seems to be
finite 3 term) sequence
1, 6, 741
741 = 3*13*19; 19-13=6
6 = 2*3; 3-2=1
Are there any other such sequences (and if such exist - are they all finite ?)
Regards,
Alexander R. Povolotsky
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