A173324 3*n! + 1.

4, 4, 7, 19, 73, 361, 2161, 15121, 120961, 1088641, 10886401, 119750401, 1437004801, 18681062401, 261534873601, 3923023104001, 62768369664001, 1067062284288001, 19207121117184001, 364935301226496001, 7298706024529920001, 153272826515128320001

Offset

0,1

Links

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

Formula

a(0) = 4, a(n) = n*a(n-1)-n+1 for n>0. - Sergei N. Gladkovskii, Jul 04 2012

Maple

a:= proc(n) if n=0 then 4 else a(n):= n*a(n-1)-n+1 fi end: seq (a(n), n=0..25);  # Sergei N. Gladkovskii, Jul 04 2012

Mathematica

Table[3 n! + 1, {n, 0, 30}] (* Vincenzo Librandi, Sep 29 2013 *)

Prog

(Magma) [3*Factorial(n) + 1: n in [0..25]]; /* or */ [4] cat [n eq 1 select n+3 else n*Self(n-1)-n+1: n in [1..25] ]; // Vincenzo Librandi, Sep 29 2013

Crossrefs

Cf. sequences of the type k*n!+1: A038507 (k=1), A052898 (k=2), this sequence, A173322 (k=4), A173319 (k=5), A173314 (k=6).

Sequence in context: A202676 A330765 A336718 * A318243 A321661 A183492

Adjacent sequences: A173321 A173322 A173323 * A173325 A173326 A173327

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 16 2010

Status

approved