A081300 Diagonal of square array A081297.

1, 5, 55, 481, 10501, 117181, 3879331, 52751105, 2351234953, 37766866501, 2120129149711, 39311679607201, 2663716583547085, 56019878838007085, 4448878347069812251, 104660471059169187841, 9534251497305019644433

Offset: 0

Author

Paul Barry, Mar 17 2003

Keywords

• easy
• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A081298, A081299, A081301, A081302.

Programs

Magma

[((n+1)^(n+3)-(-n)^(n+3))/(2*n+1): n in [0..20]]; // Vincenzo Librandi, Aug 07 2013

Mathematica

Table[((n + 1)^(n + 3) - (-n)^(n + 3)) / (2 n + 1), {n, 0, 20}] (* Vincenzo Librandi, Aug 07 2013 *)

Formula

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