A173324 - OEIS

%I #14 Sep 08 2022 08:45:50

%S 4,4,7,19,73,361,2161,15121,120961,1088641,10886401,119750401,

%T 1437004801,18681062401,261534873601,3923023104001,62768369664001,

%U 1067062284288001,19207121117184001,364935301226496001,7298706024529920001,153272826515128320001

%N 3*n! + 1.

%H Vincenzo Librandi, <a href="/A173324/b173324.txt">Table of n, a(n) for n = 0..200</a>

%F a(0) = 4, a(n) = n*a(n-1)-n+1 for n>0. - _Sergei N. Gladkovskii_, Jul 04 2012

%p 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

%t Table[3 n! + 1, {n, 0, 30}] (* _Vincenzo Librandi_, Sep 29 2013 *)

%o (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

%Y 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).

%K nonn,easy

%O 0,1

%A _Vincenzo Librandi_, Feb 16 2010