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%I #6 Feb 10 2020 11:33:28
%S 5,1,7,5,7,9,1,1,5,11,5,7,9,9,13,1,7,1,9,7,15,5,1,9,11,5,11,17,1,7,5,
%T 1,7,11,9,19,5,7,9,11,13,11,11,13,21,1,1,1,9,1,11,5,7,11,23,5,7,9,9,
%U 13,15,11,13,13,15,25,1,7,5,11,7,1,9,13,9,13,13,27
%N Triangle T(n, k) read by rows: number of different infinite-dimensional A-graded algebras with three multiplicative generators of degrees 1, k, n (1 < k < n).
%H V. I. Arnold, <a href="https://doi.org/10.1002/cpa.3160420705">A-graded algebras and continued fractions</a>, Communications on Pure and Applied Mathematics, 42 (1989), 993-1000.
%F T(n, k) = A332342(n, k) * 2 + 1 [Arnold].
%e The triangle begins:
%e n\k 2 3 4 5 6 7
%e 3| 5
%e 4| 1 7
%e 5| 5 7 9
%e 6| 1 1 5 11
%e 7| 5 7 9 9 13
%e 8| 1 7 1 9 7 15
%e ...
%Y Cf. A332342.
%K nonn,tabl
%O 3,1
%A _Andrey Zabolotskiy_, Feb 10 2020