%I #6 May 17 2016 11:49:37

%S 1,2,1,5,4,2,10,9,7,3,19,18,16,11,4,33,32,30,25,16,5,57

%N Convolve A001399 with sequences which map to 2,3,5,7,11,13,17... A000040 then, by bending when needed, summarize the results in a triangular array.

%C Apparently the terms can be constructed by fixing the generating function of the diagonal g_0(x) = 1/(1-x)/(1-x^2)/(1-x^3), A001399, and deriving the generating function of the i-th subdiagonal by g_i(x) = g_{i-1}(x)/(1-x^i), i>=1. - _R. J. Mathar_, May 17 2016

%e 1;

%e 2, 1;

%e 5, 4, 2;

%e 10, 9, 7, 3;

%e 19, 18, 16, 11, 4;

%e 33, 32, 30, 25, 16, 5;

%e 57

%Y Cf. A000098 (first column), A164678 (a similar triangle). Diagonals are A001399, A000601, A097701, A117485, ...

%K easy,nonn,tabl,uned

%O 1,2

%A _Alford Arnold_, Sep 05 2009