References to A000250

Number of symmetric reflexive relations on n nodes: (1/2)*A000666.
1, 3, 10, 45, 272, 2548, 39632, 1104306, 56871880, 5463113568, 978181717680

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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