A083072 A subdiagonal of number array A083064.

1, 4, 29, 286, 3511, 51668, 888889, 17538454, 390892451, 9720791092, 267004296901, 8031916155134, 262709978263279, 9285541905849316, 352765522430193905, 14337731083770642838, 620867368421052631579, 28539845370327607300004, 1388094251645816694624061, 71223858612700223718185374

Offset

0,2

Links

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

Formula

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

a(n) ~ exp(4-8/n) * n^n. - Amiram Eldar, Feb 06 2026

Mathematica

a[n_] := ((n+2)*(n+4)^n + 1)/(n+3); Array[a, 20, 0] (* Amiram Eldar, Feb 06 2026 *)

Crossrefs

Cf. A083064, A083071, A083069.

Sequence in context: A294160 A160885 A182356 * A302586 A302609 A181197

Adjacent sequences: A083069 A083070 A083071 * A083073 A083074 A083075

Keyword

easy,nonn

Author

Paul Barry, Apr 21 2003

Status

approved