A081302 Subdiagonal of square array A081297.

1, 1, 21, 61, 1891, 9633, 404713, 2997541, 159902271, 1564345201, 101406750589, 1236882490845, 94479649710811, 1382731226210881, 121677107761110993, 2079381120597925237, 207197254527662127511, 4051708966720224576081

Offset

0,3

Links

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

Formula

a(n) = ((n+3)^(n+1)-(-(n+2))^(n+1))/(2*n+5).

Mathematica

Table[((n + 3)^(n + 1) - (-(n + 2))^(n + 1)) / (2 n + 5), {n, 0, 20}] (* Vincenzo Librandi, Aug 08 2013 *)

Prog

(Magma) [((n+3)^(n+1)-(-(n+2))^(n+1))/(2*n+5): n in [0..20]]; // Vincenzo Librandi, Aug 08 2013

Crossrefs

Cf. A081298, A081299, A081300, A081301.

Sequence in context: A124714 A126375 A146468 * A058100 A219856 A371112

Adjacent sequences: A081299 A081300 A081301 * A081303 A081304 A081305

Keyword

easy,nonn

Author

Paul Barry, Mar 17 2003

Status

approved