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%I #6 Feb 20 2022 14:45:25
%S 1,1,2,4,1,3,2,5,1,4,7,2,6,1,5,3,8,2,7,1,6,10,3,9,2,8,1,7,4,11,3,10,2,
%T 9,1,8,13,4,12,3,11,2,10,1,9,5,14,4,13,3,12,2,11,1,10,16,5,15,4,14,3,
%U 13,2,12,1,11,6,17,5,16,4,15,3,14,2,13
%N A051340 * A128174.
%C Row sums = A014255: (1, 3, 8, 12, 21, 27, 40, ...).
%C Left border = A123684: (1, 1, 4, 2, 7, 3, 10, 4, ...).
%F A051340 * A128174 as infinite lower triangular matrices.
%e First few rows of the triangle:
%e 1;
%e 1, 2;
%e 4, 1, 3;
%e 2, 5, 1, 4;
%e 7, 2, 6, 1, 5;
%e 3, 8, 2, 7, 1, 6;
%e 10, 3, 9, 2, 8, 1, 7;
%e ...
%p A128174 := proc(n,k)
%p if k > n or k < 1 then
%p 0;
%p else
%p modp(k+n+1,2) ;
%p end if;
%p end proc:
%p A051340 := proc(n,k)
%p if k = n then
%p n ;
%p elif k <= n then
%p 1;
%p else
%p 0;
%p end if;
%p end proc:
%p A130266 := proc(n,k)
%p add( A051340(n,j)*A128174(j,k),j=k..n) ;
%p end proc:
%p seq(seq(A130266(n,k),k=1..n),n=1..15) ; # _R. J. Mathar_, Aug 06 2016
%Y Cf. A051340, A128174, A014255, A123684.
%K nonn,tabl,easy
%O 0,3
%A _Gary W. Adamson_, May 18 2007
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