OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..524
MAPLE
f:= proc(n) local N; N:= n!; ceil(N^(1/3))^3 - N end proc:
seq(f(n), n=1..30); # Robert Israel, Aug 04 2014
MATHEMATICA
f[n_] := Block[{c = n! - 1}, (1 + Floor[c^(1/3)])^3 - c - 1]; Array[f, 26] (* Robert G. Wilson v, Aug 04 2014 *)
PROG
(PARI)
a(n)=for(k=0, 10^10, s=n!+k; if((ispower(s)&&ispower(s)%3==0)||s==1, return(k)))
n=1; while(n<20, print1(a(n), ", "); n++)
(PARI) vector(50, n, ceil(n!^(1/3))^3-n!) \\ faster program
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Aug 03 2014
EXTENSIONS
a(15) onward from Robert G. Wilson v, Aug 04 2014
STATUS
approved