1,1
Table of n, a(n) for n=1..9.
D. P. Robbins, Symmetry classes of alternating sign matrices, arXiv:math/0008045 [math.CO], 2000.
a(n) = A005162(2*n).
Even numbered terms of A005162.
Cf. A059475
Sequence in context: A151879 A191552 A154828 * A191507 A191602 A145157
Adjacent sequences: A057626 A057627 A057628 * A057630 A057631 A057632
nonn,more,nice
N. J. A. Sloane, Oct 10 2000
a(8)-a(9) from A005162(2*n) by Jinyuan Wang, Mar 03 2020
approved
