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%I #6 Jul 20 2026 13:12:37
%S 1,1,9,257,24965,8345689,9935994469,43261888985391,701406030410472869,
%T 42845177964745860920417,9938256402369122699965809521,
%U 8802585608898158202243879762364131,29897291984353719865179845912465281152501,390696408699742023679820463405166732774299014481
%N Number of n X n symmetric nonnegative integer matrices with each row sum nonzero and at most n.
%Y Main diagonal of A397930.
%Y Cf. A398070.
%K nonn,new
%O 0,3
%A _Andrew Howroyd_, Jul 17 2026