A236369 4^n! - 3^n! + 2^n! - 1.

2, 2, 10, 3430, 281192563951390, 1766847064778382532572997586311708103976882383055495099549785723721857950

Offset

0,1

Comments

The next term has 434 digits. - Harvey P. Dale, Nov 04 2017

Links

Table of n, a(n) for n=0..5.

Formula

a(n)=4^n!-3^n!+2^n!-1.

Example

For n=2, a(2)=4^2!-3^2!+2^2!-1=16-9+4-1=10.

Mathematica

4^#-3^#+2^#-1&/@(Range[0, 5]!) (* Harvey P. Dale, Nov 04 2017 *)

Prog

(PARI) a(n)=(k->4^k-3^k+2^k-1)(n!) \\ Charles R Greathouse IV, Jan 23 2014

Crossrefs

Cf. A203925, A236368.

Sequence in context: A069240 A000371 A081088 * A001038 A283454 A027623

Adjacent sequences: A236366 A236367 A236368 * A236370 A236371 A236372

Keyword

nonn

Author

Assoul Abdelkarim, Jan 23 2014

Extensions

a(4)-a(5) from Charles R Greathouse IV, Jan 23 2014

Status

approved