A059495 For odd p such that 2^p-1 is a prime (A000043), write 2^p-1 = x^2+3*y^2; sequence gives values of y.

1, 3, 3, 45, 3, 381, 2349, 115329357, 10279641655875, 5033685952807971, 5263826472436016979, 898670952308059000662208200339860406351380028634597445743368513219427297854627, 1163046333059983884005407440923089001865672520479660324278034104804471332063117356524700189

Offset

1,2

References

F. Lemmermeyer, Reciprocity Laws From Euler to Eisenstein, Springer-Verlag, 2000, p. 59.

Links

Table of n, a(n) for n=1..13.

Phil Moore, Tony Reix and others, Online Discussion

Example

p=7: 127 = 10^2 + 3*3^2, so a(3) = 3.

Crossrefs

Cf. A000043, A000668, A059494.

Sequence in context: A368162 A269909 A231989 * A372423 A174325 A290366

Adjacent sequences: A059492 A059493 A059494 * A059496 A059497 A059498

Keyword

nonn,easy

Author

N. J. A. Sloane, Feb 05 2001

Extensions

More terms from Joshua Zucker, May 23 2006

Status

approved