This pattern was made using the Quantum Phase Estimation algorithm, and Qiskit's QASM simulator. Each pixel colour is calculated from the resuts of a different quantum circuit, parameterised by it's distance from the centre of the image.
Great new section in the @qiskit textbook by @anedumlACV focusing on solving linear systems of equations using the HHL algorithm! It has examples of the algorithm for a few qubits, and runs HHL using Qiskit Aqua on both simulators and real hardware.
qiskit.org/textbook/ch-ap…