References to A000245

3*(2*n)!/((n+2)!*(n-1)!).
0, 1, 3, 9, 28, 90, 297, 1001, 3432, 11934, 41990, 149226, 534888, 1931540

1 seqfan posts

Fri Oct 29 05:35:16 CEST 2010    [seqfan] Implementing first 500 sequences in Java
Index of A-numbers in seqfan: by ascending order    by month    by frequency    by keyword
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