login
Nearest integer to 1/sum(k>n,1/k^5).
0

%I #8 Dec 02 2012 14:24:44

%S 1,27,176,640,1707,3760,7280,12842,21120,32880,48986,70400,98176,

%T 133466,177520,231680,297386,376176,469680,579626,707840,856240,

%U 1026842,1221760,1443200,1693466,1974960,2290176,2641706,3032240,3464560

%N Nearest integer to 1/sum(k>n,1/k^5).

%F n>2 a(n)=floor(4*n^4-8*n^3+28/3*n^2-16/3*n)

%F Empirical G.f.: x*(x^11-4*x^10+6*x^9-4*x^8+2*x^7-4*x^6-21*x^5-73*x^4-93*x^3-74*x^2-23*x-1) / ((x-1)^5*(x^2+x+1)). [_Colin Barker_, Dec 01 2012]

%o (PARI) a(n)=round(1/(zeta(5)-sum(k=1,n-1,1/k^5)))

%Y Cf. A001844.

%K nonn

%O 1,2

%A _Benoit Cloitre_, Jun 12 2003