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Square array A(row,col) (listed in order A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), etc.), giving essentially the same information as the triangle A074080 which shows only the upper triangular region.
5

%I #5 May 01 2014 02:48:25

%S 1,1,0,0,0,0,1,1,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,1,0,0,0,0,1,0,2,1,0,0,

%T 0,0,0,0,3,2,0,0,0,0,0,0,1,3,5,1,0,0,0,0,0,0,1,3,10,3,0,0,0,0,0,0,0,0,

%U 3,17,9,1,0,0,0,0,0,0,0,1,5,28,24,4,0,0,0,0,0,0,0,0,0,4,41,57,14,1,0,0,0

%N Square array A(row,col) (listed in order A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), etc.), giving essentially the same information as the triangle A074080 which shows only the upper triangular region.

%F A074079(n, k) = A073346(n, k)/(2^k)

%p A074079bi := (n,k) -> A073346bi(n,k)/(2^k);

%p A074079 := n -> A074079bi(A025581(n), A002262(n));

%p A025581 := n -> binomial(1+floor((1/2)+sqrt(2*(1+n))),2) - (n+1);

%p A002262 := n -> n - binomial(floor((1/2)+sqrt(2*(1+n))),2);

%Y Obtained from the square array A073346 by dividing the entries on the k-th row by 2^k. Column sums: A073431. See A074080 for explanation. Cf. also A025581, A002262.

%K nonn,tabl

%O 0,31

%A _Antti Karttunen_, Aug 19 2002