Euler (or secant or "Zig") numbers: e.g.f. (even powers only) sech(x)=1/cosh(x).
1, 1, 5, 61, 1385, 50521, 2702765, 199360981, 19391512145, 2404879675441
2 seqfan posts
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java
Tue Nov 10 05:57:30 CET 2009 [seqfan] Surprising Patterns in Tangent and Secant Numbers
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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