A066256 a(n) = k that produces the smallest integer m > 1 of the form m = (k^2 + n)/(n^2 + k).

5, 5, 10, 10, 26, 37, 12, 65, 30, 27, 38, 145, 109, 197, 226, 62, 290, 129, 108, 401, 442, 69, 56, 577, 130, 48, 730, 464, 105, 103, 300, 220, 1090, 363, 147, 222, 194, 1445, 184, 902, 1682, 387, 588, 390, 391, 263, 258, 133, 350, 2501, 2119, 1484, 549, 2917

Offset

2,1

Comments

The function m(k) is a monotonically increasing function of k if n is held constant. Therefore the implementation may scan k upwards until the first integer m is found. - R. J. Mathar, Aug 07 2014

Links

Vincenzo Librandi, Table of n, a(n) for n = 2..250

Maple

A066256 := proc(n)
    local k, f ;
    for k from 1 do
        f  := (k^2+n)/(n^2+k) ;
        if f > 1 and  type(f, 'integer') then
            return k;
        end if;
    end do:
end proc: # R. J. Mathar, Aug 07 2014

Mathematica

Do[k = 1; While[m = (k^2 + n)/(n^2 + k); !IntegerQ[m] || m == 1, k++ ]; Print[k], {n, 2, 75} ]

Crossrefs

Cf. A066257.

Sequence in context: A003882 A168284 A166598 * A029842 A112436 A309457

Adjacent sequences: A066253 A066254 A066255 * A066257 A066258 A066259

Keyword

nonn

Author

Benoit Cloitre, Dec 31 2001

Extensions

More terms from Robert G. Wilson v, Jan 03 2002

Status

approved