cp's OEIS Frontend

A347274 a(n) = Sum_{j=1..n} j*n^(n+1-j).

%I A347274 #31 Sep 12 2021 12:45:21
%S A347274 1,8,54,448,4875,67176,1120924,21913088,490329045,12345679000,
%T A347274 345227121426,10610896401216,355457590375615,12887297856860168,
%U A347274 502684312937211000,20988295479420645376,933876701895122362665,44111544001370512714296,2204350295349917301462190
%N A347274 a(n) = Sum_{j=1..n} j*n^(n+1-j).
%F A347274 a(n) = (n^n - n)*(n/(n-1))^2 for n > 1, a(1) = 1.
%F A347274 a(n) = n * A062805(n) = n^2 * A058128(n) = n^3 * A060073(n).
%e A347274 a(1) = 1;
%e A347274 a(2) = 2^2 + 2*2^1 = 8;
%e A347274 a(3) = 3^3 + 2*3^2 + 3*3^1 = 54;
%e A347274 a(4) = 4^4 + 2*4^3 + 3*4^2 + 4*4^1 = 448;
%e A347274 a(5) = 5^5 + 2*5^4 + 3*5^3 + 4*5^2 + 5*5^1 = 4875.
%p A347274 a:= n-> `if`(n=1, 1, (n^n-n)*(n/(n-1))^2):
%p A347274 seq(a(n), n=1..20);  # _Alois P. Heinz_, Sep 02 2021
%o A347274 (Python)
%o A347274 def A347274(n): return 1 if n == 1 else n**2*(n**n-n)//(n - 1)**2 # _Chai Wah Wu_, Sep 12 2021
%Y A347274 Cf. A058128, A060073, A062805.
%K A347274 nonn
%O A347274 1,2
%A A347274 _Ryan Stubbs_, Aug 25 2021