OFFSET
1,2
COMMENTS
If w6(n) = sum a(n) q^n and w4(n) = sum 5 sigma_3(n) q^n then the Tate elliptic curve is y^2 + xy = x^3 - w4(q)x - w6(q) If |q|<1 (for either real, complex, or p-adic values) and the resulting curve is nonsingular we have an elliptic curve. The parametrization is especially useful p-adically, behaving well in characteristic 2 or 3.
REFERENCES
Joseph H. Silverman, "Advanced Topics in the Arithmetic of Elliptic Curves", Springer, 1994
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
H. D. Nguyen, D. Taggart, Mining the OEIS: Ten Experimental Conjectures, 2013. Mentions this sequence. - From N. J. A. Sloane, Mar 16 2014
FORMULA
MATHEMATICA
Table[(5*DivisorSigma[3, n]+7*DivisorSigma[5, n])/12, {n, 30}] (* Harvey P. Dale, May 02 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gene Ward Smith, Aug 22 2006
STATUS
approved