OFFSET
1,1
COMMENTS
The sum of the reciprocals = 0.595091701724608076103001212.. Converges rapidly.
FORMULA
floor( sqrt(1/x)*10^(floor(sqrt(x))) )
MATHEMATICA
Table[Floor[Sqrt[1/x] 10^Floor[Sqrt[x]]], {x, 50}] (* Harvey P. Dale, Feb 01 2022 *)
PROG
(PARI) rootrecip(n) = { sr=0; for(x=1, n, r =sqrt(x); ip=floor(r); fp=r-ip; y=floor((1/r)*10^ip); print1(y", "); sr = sr + 1.0/y; ); print(); print(sr) }
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Dec 11 2003
STATUS
approved