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A201225
Values x for infinite sequence x^3-y^2 = d with decreasing coefficient r=sqrt(x)/d which tend to 1/(1350*sqrt(5))or infinity family of solutions Mordell curve with extension sqrt(5).
3
6100, 2305180, 748476100, 241118603980, 77641444770100, 25000340035616380, 8050032494909496100, 2592085474592828222380, 834643472994047002110100, 268752606222334691877221980, 86537504560185639786707316100, 27864807715774753485364243735180
OFFSET
1,1
COMMENTS
a(1) = A200656(4) = A201047(4).
a(2) = A200656(36) = A201047(26).
All points in this sequence are extremal points (definition see A200656) and from these reason is subset of A200656 and primary (definition see A200656) and from these reason is subset of A201047.
FORMULA
G.f.: (20*(-305-11254*z+7424*z^2-346*z^3+z^4))/((-1+z)*(1- 322*z+z^2)*(1-18*z+z^2)).
a(n) = 341*a(n-1) - 6138*a(n-2) + 6138*a(n-3) - 341*a(n-4) + a(n-5).
MATHEMATICA
LinearRecurrence[{341, -6138, 6138, -341, 1}, {6100, 2305180, 748476100, 241118603980, 77641444770100}, 20] (* Harvey P. Dale, Aug 17 2016 *)
CROSSREFS
Sequence in context: A236824 A211929 A251994 * A031619 A235764 A235547
KEYWORD
nonn
AUTHOR
Artur Jasinski, Nov 28 2011
STATUS
approved