%I #30 May 25 2021 10:31:24

%S 2,5,19,205,3011,92875,4763459,459630701,78223965193,24270274906085,

%T 13497818986883771,13571363009654254429,24562890586806439035377,

%U 80199120146273882569630015,471874707649862024071657639861,5005895207027974222377733802848093

%N Number of ways to place k non-attacking kings on an n X n cylindrical chessboard, summed over all k >= 0.

%D S. R. Finch, Mathematical Constants, Cambridge, 2003, p. 343.

%H Vaclav Kotesovec, <a href="/A212269/b212269.txt">Table of n, a(n) for n = 1..27</a>

%H V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p.165

%F Limit n ->infinity (a(n))^(1/n^2) = 1.342643951124... (see A247413).

%Y Cf. A063443(n+1), A067958, A194650-A194654, A182407, A247413, A212269.

%K nonn,hard

%O 1,1

%A _Vaclav Kotesovec_, May 12 2012