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A276456 Integers n such that the Klein invariant J((-1+sqrt(-n))/2) is a rational number. 0
1, 3, 7, 11, 19, 27, 43, 67, 163 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Probably sequence is finite and complete.
This sequence looks very much like A003173, the Heegner numbers, except for two terms (add 2, remove 27). Is there a proof of this connection? - Luc Rousseau, Nov 30 2017
LINKS
EXAMPLE
a(1) = 1 because J((-1+sqrt(-1))/2) = 1;
a(2) = 3 because J((-1+sqrt(-3))/2) = 0;
a(3) = 7 because J((-1+sqrt(-7))/2) = -125/64;
a(4) = 11 because J((-1+sqrt(-11))/2) = -512/27;
a(5) = 19 because J((-1+sqrt(-19))/2) = -512;
a(6) = 27 because J((-1+sqrt(-27))/2) = -64000/9;
a(7) = 43 because J((-1+sqrt(-43))/2) = -512000;
a(8) = 67 because J((-1+sqrt(-67))/2) = -85184000;
a(9) = 163 because J((-1+sqrt(-163))/2) = -151931373056000.
CROSSREFS
Sequence in context: A292095 A265323 A346912 * A126254 A092102 A158722
KEYWORD
nonn
AUTHOR
Artur Jasinski, Sep 03 2016
STATUS
approved

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Last modified March 28 15:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)