A083082 First subdiagonal of number array A083075.

1, 5, 61, 1065, 23801, 650893, 21120373, 794552657, 34040573425, 1637411510421, 87420145670573, 5131440522974329, 328542298690792681, 22789709877615373085, 1702810951672313083621, 136361486383932674632353, 11652094585649546008814561, 1058320536486348164045402917

Offset

0,2

Links

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

Formula

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

a(n) ~ exp(5/2-25/(8*n)) * (2*n)^n. - Amiram Eldar, Feb 05 2026

Mathematica

Table[((n+1)(2n+5)^n+1)/(n+2), {n, 0, 20}] (* Harvey P. Dale, Oct 06 2019 *)

Prog

(Magma) [((n+1)*(2*n+5)^n+1)/(n+2): n in [0..20]]; // Vincenzo Librandi, Nov 12 2011

Crossrefs

Cf. A083075, A083080, A083083.

Sequence in context: A390303 A146760 A294024 * A213110 A298695 A352238

Adjacent sequences: A083079 A083080 A083081 * A083083 A083084 A083085

Keyword

easy,nonn

Author

Paul Barry, Apr 23 2003

Status

approved