A059423 Number of positive terms in a symmetric determinant of order n.

1, 1, 1, 2, 8, 38, 193, 1243, 8971, 77039, 711719, 7557974, 85038784, 1075040038, 14252911927, 208885729397, 3187988600057, 53129157538097, 917244939572929, 17127419083026706, 329981266766790136, 6823452191056396526, 145118585159785011041

Offset: 0

Author

N. J. A. Sloane, Jan 30 2001

Keywords

• nonn

References

• L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 260, #12, p_n.

Crossrefs

(A002135+A059422)/2. Cf. A059424.