%I #12 Mar 28 2024 21:54:30
%S 1,13,229,4921,128841,4022341,146450893,6103787761,286833509137,
%T 15011892880381,866190689012661,54637591044108073,3740820141248285785,
%U 276304073198956644661,21900911192388373534621
%N First superdiagonal of number array A083075.
%H Vincenzo Librandi, <a href="/A083081/b083081.txt">Table of n, a(n) for n = 1..300</a>
%F a(n) = ((n-1)*(2n+1)^n + 1)/n.
%o (Magma) [((n-1)*(2*n+1)^n+1)/n: n in [1..20]]; // _Vincenzo Librandi_, Nov 12 2011
%Y Cf. A083080, A083082.
%K easy,nonn
%O 1,2
%A _Paul Barry_, Apr 23 2003