A229828 a(n) = 7*n! - 1.

6, 6, 13, 41, 167, 839, 5039, 35279, 282239, 2540159, 25401599, 279417599, 3353011199, 43589145599, 610248038399, 9153720575999, 146459529215999, 2489811996671999, 44816615940095999, 851515702861823999, 17030314057236479999, 357636595201966079999

Offset: 0

Author

Vincenzo Librandi, Sep 30 2013

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. sequences of the type k*n!-1: A033312 (k=1), A020543 (k=2), A173323 (k=3), A173321 (k=4), A173317 (k=5), A173316 (k=6).

Programs

Magma

[7*Factorial(n)-1: n in [0..25]];

Magma

[6] cat [n eq 1 select n+5 else n*Self(n-1)+n-1: n in [1..25] ];

Mathematica

Table[7 n! - 1, {n, 0, 25}]

Formula

a(0)=6, a(n) = n*a(n-1)+n-1.