Ten years later, at a used book sale, I came across the Collected Papers of Ramanujan, and one particular paper caught my eye: Modular equations and approximations to π. You can see he is hot on the trail!
Below is my program of learning. I want to understand all this about the j-invariant, what is a class number, and why the j-invariant is an integer at these special points.
“Introduction to Modular Forms,” by Keith Conrad.
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"A Short Course on Modular Forms" by Prof. M. Ram Murty
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"j-function", a Wolfram notebook
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"Class number statistics for imaginary quadratic fields" by Pär Kurlberg
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"Gauss' class number problem for imaginary quadratic fields" by Dorian Goldfeld
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"Modular curves and the class number one problem" by Jeremy Booher
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