This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A222637 Squarefree part of the total number of arrangements of a set with n elements. 4

%I

%S 1,2,5,1,65,326,1957,137,109601,986410,9864101,27126278,7704505,

%T 16926797486,236975164805,888656868019,56874039553217,966858672404690,

%U 17403456103284421,826664164906010,6613313319248080001,138879579704209680022,3055350753492612960485

%N Squarefree part of the total number of arrangements of a set with n elements.

%D F. Luca and I. E. Shparlinski, On the squarefree parts of [ e n! ], Glasgow Math. J., 49 (2007), 391-403.

%F a(n) = core(A000522(n)).

%p A000522 := proc(n)

%p end proc:

%p A222637 := proc(n)

%p A007913(A000522(n)) ;

%p end proc: # _R. J. Mathar_, Jan 16 2014

%o (PARI) a(n) = core(n! * polcoeff(exp(x + x*O(x^n)) / (1 - x), n))

%Y Cf. A000522, A007913, A222638, A222639.

%K nonn

%O 0,2

%A _Michel Marcus_, Feb 27 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 15 22:20 EST 2018. Contains 317252 sequences. (Running on oeis4.)