A074079 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.

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, 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, 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

Offset

0,31

Links

Table of n, a(n) for n=0..100.

Formula

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

Maple

A074079bi := (n, k) -> A073346bi(n, k)/(2^k);
A074079 := n -> A074079bi(A025581(n), A002262(n));
A025581 := n -> binomial(1+floor((1/2)+sqrt(2*(1+n))), 2) - (n+1);
A002262 := n -> n - binomial(floor((1/2)+sqrt(2*(1+n))), 2);

Crossrefs

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.

Sequence in context: A361430 A298826 A374246 * A037858 A037876 A263774

Adjacent sequences: A074076 A074077 A074078 * A074080 A074081 A074082

Keyword

nonn,tabl

Author

Antti Karttunen, Aug 19 2002

Status

approved