A083071 First subdiagonal of number array A083064.

1, 3, 19, 173, 2001, 28087, 465011, 8888889, 192922993, 4690709411, 126370284195, 3738060156613, 120478742327009, 4203359652212463, 157854212399438371, 6349779403743490289, 272416890591642213921, 12417347368421052631579, 599336752776879753300083, 30538073536207967281729341

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

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

a(n) ~ exp(3-9/(2*n)) * n^n. - Amiram Eldar, Feb 06 2026

Mathematica

a[n_] := ((n+1)*(n+3)^n + 1)/(n+2); Array[a, 20, 0] (* Amiram Eldar, Feb 06 2026 *)

Crossrefs

Cf. A083064, A083069, A083070.

Sequence in context: A353256 A275283 A349768 * A379194 A305459 A045531

Adjacent sequences: A083068 A083069 A083070 * A083072 A083073 A083074

Keyword

easy,nonn

Author

Paul Barry, Apr 21 2003

Status

approved