A066018 a(n) is the smallest k such that (k^4 + 1)/(n^4 + 1) is an integer > 1.

3, 8, 27, 64, 125, 216, 343, 474, 43, 781, 1331, 1728, 2197, 1807, 3375, 4096, 4913, 1600, 807, 8000, 9261, 10648, 12167, 13824, 7353, 17576, 6721, 21952, 24389, 27000, 29791, 32768, 35937, 39304, 42875, 46656, 50653, 4015, 59319, 20723

Offset: 1

Author

Robert G. Wilson v, Dec 11 2001

Keywords

• easy
• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 1..250

Crossrefs

Cf. A065964.

Programs

Mathematica

Do[k = 1; While[m = (k^4 + 1)/(n^4 + 1); m < 2 || !IntegerQ[m], k++ ]; Print[k], {n, 1, 40} ]

PARI

{ for (n=1, 250, f=n^4 + 1; a=n + 1; while (frac((a^4 + 1)/f) !=0, a++); write("b066018.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 06 2009