%I #8 Sep 08 2022 08:45:10
%S 1,3,33,547,11713,309411,9763393,359046339,15096500481,714852041923,
%T 37660464739681,2185503641764323,138548894120306881,
%U 9527726662032987747,706481006206076565633,56192761405186331759491
%N Main diagonal of number array A083075.
%H Vincenzo Librandi, <a href="/A083080/b083080.txt">Table of n, a(n) for n = 0..300</a>
%F a(n) = (n*(2n+3)^n + 1)/(n+1).
%o (Magma) [(n*(2*n+3)^n+1)/(n+1): n in [0..20]]; // _Vincenzo Librandi_, Nov 12 2011
%Y Cf. A083081, A083082.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Apr 23 2003