I think you have three options.
1) 4S 1500mA each LED 306.9lm 3.14V 4.71W. Total 4 LEDs 1,227.6lm 12.56V 18.84W.
2) 2S2P 750mA each LED 166lm 2.92V 2.19W. Total 4 LEDs 664lm 5.84V 8.76W.
3) 4P 375mA each LED 85lm 2.77V 1.03W. Total 4 LEDs 340lm 2.77V 4.12W.
If you want the brightest output, you should connect them in 4S and the supplied voltage higher than 14V.