A173317 5*n! - 1.

4, 4, 9, 29, 119, 599, 3599, 25199, 201599, 1814399, 18143999, 199583999, 2395007999, 31135103999, 435891455999, 6538371839999, 104613949439999, 1778437140479999, 32011868528639999, 608225502044159999

Offset

0,1

Links

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

Formula

a(n) = 5*A000142(n)-1.

a(0)=4, a(n) = n*a(n-1)+n-1. - Vincenzo Librandi, Sep 30 2013

Mathematica

Table[5 n! - 1, {n, 0, 25}] (* Vincenzo Librandi, Sep 30 2013 *)

Prog

(Magma) [5*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 30 2013

Crossrefs

Cf. sequences of the type k*n!-1: A033312 (k=1), A020543 (k=2), A173323 (k=3), A173321 (k=4), this sequence, A173316 (k=6).

Sequence in context: A324010 A117416 A174943 * A059811 A202409 A091016

Adjacent sequences: A173314 A173315 A173316 * A173318 A173319 A173320

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 16 2010

Extensions

a(16) corrected from Vincenzo Librandi, Sep 30 2013

Status

approved