A367255 - OEIS

%I #8 Dec 01 2023 04:40:27

%S 1,2,7,40,325,3456,45619,720896,13286025,280000000,6645125311,

%T 175432531968,5100764198413,161982606786560,5579092529296875,

%U 207165582859042816,8250513501410645521,350825312056827838464,15864277746219164222455,760217600000000000000000

%N a(n) = (n + 1)^(n - 2)*(3*n + 1).

%F a(n) = Sum_{k=0..n} binomial(n - 1, k - 1) * n^(n - k) * (k + 1). (See A137452.)

%p a := n -> (n + 1)^(n - 2)*(3*n + 1): seq(a(n), n = 0..19);

%t A367255[n_]:=(n+1)^(n-2)(3n+1);

%t Array[A367255,25,0] (* _Paolo Xausa_, Dec 01 2023 *)

%Y Cf. A137452.

%K nonn

%O 0,2

%A _Peter Luschny_, Nov 11 2023