A083084 A diagonal of number array A083075.

1, 9, 141, 2893, 73081, 2200977, 77189509, 3095295861, 139872233073, 7039013063065, 390656716635901, 23714578436644509, 1563646420268423401, 111315499088924632353, 8511391223995285616373, 695805743909499121660357, 60571079368920401629111009, 5594669625105161922742432041

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Formula

a(n) = ((n+3)*(2n+9)^n + 1)/(n+4).

a(n) ~ exp(9/2-81/(8*n)) * (2*n)^n. - Amiram Eldar, Feb 05 2026

Mathematica

a[n_] := ((n+3)*(2n+9)^n + 1)/(n+4); Array[a, 20, 0] (* Amiram Eldar, Feb 05 2026 *)

Prog

(Magma) [((n+3)*(2*n+9)^n+1)/(n+4): n in [0..20]]; // Vincenzo Librandi, Nov 12 2011

Crossrefs

Cf. A083075, A083083, A083082.

Sequence in context: A137059 A263966 A371365 * A187402 A385929 A363478

Adjacent sequences: A083081 A083082 A083083 * A083085 A083086 A083087

Keyword

easy,nonn

Author

Paul Barry, Apr 23 2003

Status

approved