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%I #12 Dec 26 2023 05:09:21
%S 1,2,18,250,4810,118458,3557610,126109562,5153959338,238596116794,
%T 12340467941098,705262375055610,44135963944338474,3001795007526424250,
%U 220466095716711140202,17389850740043552754298,1466156761178169939270826,131580021359494993268692026
%N a(n) = Sum_{k=0..n} 2^k * k^n.
%F a(n) ~ 2^n * n^n / (1 - exp(-1)/2). - _Vaclav Kotesovec_, Dec 26 2023
%o (PARI) a(n) = sum(k=0, n, 2^k*k^n);
%Y Main diagonal of A368479.
%Y Cf. A031971, A120485, A349963.
%K nonn,easy
%O 0,2
%A _Seiichi Manyama_, Dec 25 2023