cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A057629 Number of alternating sign 2n X 2n matrices invariant under flips in both diagonals.

Original entry on oeis.org

2, 8, 52, 568, 10436, 323144, 16866856, 1484714416, 220426128584
Offset: 1

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Author

N. J. A. Sloane, Oct 10 2000

Keywords

Crossrefs

Even numbered terms of A005162.
Cf. A059475.

Formula

a(n) = A005162(2*n).

Extensions

a(8)-a(9) from A005162(2*n) by Jinyuan Wang, Mar 03 2020