OFFSET
1,4
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = floor(n!*zeta(2)) - n*floor((n-1)!*zeta(2)), for n>=2.
MATHEMATICA
With[{b = Zeta[2]}, Table[If[n == 1, Floor[b], Floor[n!*b] - n*Floor[(n - 1)!*b]], {n, 1, 100}]] (* G. C. Greubel, Nov 26 2018 *)
PROG
(PARI) default(realprecision, 250); b = zeta(2); for(n=1, 80, print1(if(n==1, floor(b), floor(n!*b) - n*floor((n-1)!*b)), ", ")) \\ G. C. Greubel, Nov 26 2018
(Magma) SetDefaultRealField(RealField(250)); L:=RiemannZeta(); [Floor(Evaluate(L, 2))] cat [Floor(Factorial(n)*Evaluate(L, 2)) - n*Floor(Factorial((n-1))*Evaluate(L, 2)) : n in [2..80]]; // G. C. Greubel, Nov 26 2018
(Sage)
def A067279(n):
if (n==1): return floor(zeta(2))
else: return expand(floor(factorial(n)*zeta(2)) - n*floor(factorial(n-1)*zeta(2)))
[A067279(n) for n in (1..80)] # G. C. Greubel, Nov 26 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Mar 10 2002
EXTENSIONS
a(1) corrected by G. C. Greubel, Nov 26 2018
STATUS
approved