A029723 Trace of Frobenius of the reduction mod 2 of the elliptic curve C / L, L a lattice with Gram matrix [ 4 1; 1 2n ].

1, 1, 3, 1, 5, 9, 3, 1, 21, 7, 13, 13, 5

Offset

0,3

Links

Table of n, a(n) for n=0..12.

Formula

Of form sqrt(2^(h(1-8n)+2)-m^2(8n-1)), with m odd.

Crossrefs

Sequence in context: A193710 A128821 A221446 * A187370 A215456 A225855

Adjacent sequences: A029720 A029721 A029722 * A029724 A029725 A029726

Keyword

nonn

Author

Eric Rains (rains(AT)caltech.edu)

Status

approved